diff --git a/system/Database/BaseBuilder.php b/system/Database/BaseBuilder.php
index e881148a5fa7..ff67d1f5eb3c 100644
--- a/system/Database/BaseBuilder.php
+++ b/system/Database/BaseBuilder.php
@@ -39,6 +39,7 @@
 namespace CodeIgniter\Database;
 
 use CodeIgniter\Database\Exceptions\DatabaseException;
+use CodeIgniter\Database\Exceptions\DataException;
 
 /**
  * Class BaseBuilder
@@ -137,6 +138,13 @@ class BaseBuilder
 	 */
 	public $QBOrderBy = [];
 
+	/**
+	 * QB NO ESCAPE data
+	 *
+	 * @var array
+	 */
+	public $QBNoEscape = [];
+
 	/**
 	 * QB data sets
 	 *
@@ -264,11 +272,11 @@ public function getBinds(): array
 	 * Generates the SELECT portion of the query
 	 *
 	 * @param string|array $select
-	 * @param mixed        $escape
+	 * @param boolean      $escape
 	 *
 	 * @return BaseBuilder
 	 */
-	public function select($select = '*', $escape = null)
+	public function select($select = '*', bool $escape = null)
 	{
 		if (is_string($select))
 		{
@@ -317,7 +325,7 @@ public function select($select = '*', $escape = null)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function selectMax($select = '', $alias = '')
+	public function selectMax(string $select = '', string $alias = '')
 	{
 		return $this->maxMinAvgSum($select, $alias, 'MAX');
 	}
@@ -334,7 +342,7 @@ public function selectMax($select = '', $alias = '')
 	 *
 	 * @return BaseBuilder
 	 */
-	public function selectMin($select = '', $alias = '')
+	public function selectMin(string $select = '', string $alias = '')
 	{
 		return $this->maxMinAvgSum($select, $alias, 'MIN');
 	}
@@ -351,7 +359,7 @@ public function selectMin($select = '', $alias = '')
 	 *
 	 * @return BaseBuilder
 	 */
-	public function selectAvg($select = '', $alias = '')
+	public function selectAvg(string $select = '', string $alias = '')
 	{
 		return $this->maxMinAvgSum($select, $alias, 'AVG');
 	}
@@ -368,7 +376,7 @@ public function selectAvg($select = '', $alias = '')
 	 *
 	 * @return BaseBuilder
 	 */
-	public function selectSum($select = '', $alias = '')
+	public function selectSum(string $select = '', string $alias = '')
 	{
 		return $this->maxMinAvgSum($select, $alias, 'SUM');
 	}
@@ -388,13 +396,19 @@ public function selectSum($select = '', $alias = '')
 	 * @param string $type
 	 *
 	 * @return BaseBuilder
+	 * @throws \CodeIgniter\Database\Exceptions\DataException
 	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
 	 */
-	protected function maxMinAvgSum($select = '', $alias = '', $type = 'MAX')
+	protected function maxMinAvgSum(string $select = '', string $alias = '', string $type = 'MAX')
 	{
-		if (! is_string($select) || $select === '')
+		if ($select === '')
 		{
-			throw new DatabaseException('The query you submitted is not valid.');
+			throw DataException::forEmptyInputGiven('Select');
+		}
+
+		if (strpos($select, ',') !== false)
+		{
+			throw DataException::forInvalidArgument('column name not separated by comma');
 		}
 
 		$type = strtoupper($type);
@@ -426,7 +440,7 @@ protected function maxMinAvgSum($select = '', $alias = '', $type = 'MAX')
 	 *
 	 * @return string
 	 */
-	protected function createAliasFromTable($item)
+	protected function createAliasFromTable(string $item): string
 	{
 		if (strpos($item, '.') !== false)
 		{
@@ -449,9 +463,9 @@ protected function createAliasFromTable($item)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function distinct($val = true)
+	public function distinct(bool $val = true)
 	{
-		$this->QBDistinct = is_bool($val) ? $val : true;
+		$this->QBDistinct = $val;
 
 		return $this;
 	}
@@ -468,7 +482,7 @@ public function distinct($val = true)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function from($from, $overwrite = false)
+	public function from($from, bool $overwrite = false)
 	{
 		if ($overwrite === true)
 		{
@@ -510,14 +524,14 @@ public function from($from, $overwrite = false)
 	 *
 	 * Generates the JOIN portion of the query
 	 *
-	 * @param string $table
-	 * @param string $cond   The join condition
-	 * @param string $type   The type of join
-	 * @param string $escape Whether not to try to escape identifiers
+	 * @param string    $table
+	 * @param string    $cond   The join condition
+	 * @param string    $type   The type of join
+	 * @param boolean   $escape Whether not to try to escape identifiers
 	 *
 	 * @return BaseBuilder
 	 */
-	public function join($table, $cond, $type = '', $escape = null)
+	public function join(string $table, string $cond, string $type = '', bool $escape = null)
 	{
 		if ($type !== '')
 		{
@@ -605,7 +619,7 @@ public function join($table, $cond, $type = '', $escape = null)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function where($key, $value = null, $escape = null)
+	public function where($key, $value = null, bool $escape = null)
 	{
 		return $this->whereHaving('QBWhere', $key, $value, 'AND ', $escape);
 	}
@@ -624,7 +638,7 @@ public function where($key, $value = null, $escape = null)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function orWhere($key, $value = null, $escape = null)
+	public function orWhere($key, $value = null, bool $escape = null)
 	{
 		return $this->whereHaving('QBWhere', $key, $value, 'OR ', $escape);
 	}
@@ -647,7 +661,7 @@ public function orWhere($key, $value = null, $escape = null)
 	 *
 	 * @return BaseBuilder
 	 */
-	protected function whereHaving($qb_key, $key, $value = null, $type = 'AND ', $escape = null)
+	protected function whereHaving(string $qb_key, $key, $value = null, string $type = 'AND ', bool $escape = null)
 	{
 		if (! is_array($key))
 		{
@@ -689,6 +703,8 @@ protected function whereHaving($qb_key, $key, $value = null, $type = 'AND ', $es
 				{
 					$k .= $op;
 				}
+
+				$v = " :$bind:";
 			}
 			elseif (! $this->hasOperator($k))
 			{
@@ -700,8 +716,6 @@ protected function whereHaving($qb_key, $key, $value = null, $type = 'AND ', $es
 				$k = substr($k, 0, $match[0][1]) . ($match[1][0] === '=' ? ' IS NULL' : ' IS NOT NULL');
 			}
 
-			$v = ! is_null($v) ? " :$bind:" : $v;
-
 			$this->{$qb_key}[] = [
 				'condition' => $prefix . $k . $v,
 				'escape'    => $escape,
@@ -725,7 +739,7 @@ protected function whereHaving($qb_key, $key, $value = null, $type = 'AND ', $es
 	 *
 	 * @return BaseBuilder
 	 */
-	public function whereIn($key = null, $values = null, $escape = null)
+	public function whereIn(string $key = null, array $values = null, bool $escape = null)
 	{
 		return $this->_whereIn($key, $values, false, 'AND ', $escape);
 	}
@@ -744,7 +758,7 @@ public function whereIn($key = null, $values = null, $escape = null)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function orWhereIn($key = null, $values = null, $escape = null)
+	public function orWhereIn(string $key = null, array $values = null, bool $escape = null)
 	{
 		return $this->_whereIn($key, $values, false, 'OR ', $escape);
 	}
@@ -763,7 +777,7 @@ public function orWhereIn($key = null, $values = null, $escape = null)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function whereNotIn($key = null, $values = null, $escape = null)
+	public function whereNotIn(string $key = null, array $values = null, bool $escape = null)
 	{
 		return $this->_whereIn($key, $values, true, 'AND ', $escape);
 	}
@@ -782,7 +796,7 @@ public function whereNotIn($key = null, $values = null, $escape = null)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function orWhereNotIn($key = null, $values = null, $escape = null)
+	public function orWhereNotIn(string $key = null, array $values = null, bool $escape = null)
 	{
 		return $this->_whereIn($key, $values, true, 'OR ', $escape);
 	}
@@ -805,18 +819,13 @@ public function orWhereNotIn($key = null, $values = null, $escape = null)
 	 *
 	 * @return BaseBuilder
 	 */
-	protected function _whereIn($key = null, $values = null, $not = false, $type = 'AND ', $escape = null)
+	protected function _whereIn(string $key = null, array $values = null, bool $not = false, string $type = 'AND ', bool $escape = null)
 	{
 		if ($key === null || $values === null)
 		{
 			return $this;
 		}
 
-		if (! is_array($values))
-		{
-			$values = [$values];
-		}
-
 		is_bool($escape) || $escape = $this->db->protectIdentifiers;
 
 		$ok = $key;
@@ -859,7 +868,7 @@ protected function _whereIn($key = null, $values = null, $not = false, $type = '
 	 *
 	 * @return BaseBuilder
 	 */
-	public function like($field, $match = '', $side = 'both', $escape = null, $insensitiveSearch = false)
+	public function like($field, string $match = '', string $side = 'both', bool $escape = null, bool $insensitiveSearch = false)
 	{
 		return $this->_like($field, $match, 'AND ', $side, '', $escape, $insensitiveSearch);
 	}
@@ -880,7 +889,7 @@ public function like($field, $match = '', $side = 'both', $escape = null, $insen
 	 *
 	 * @return BaseBuilder
 	 */
-	public function notLike($field, $match = '', $side = 'both', $escape = null, $insensitiveSearch = false)
+	public function notLike($field, string $match = '', string $side = 'both', bool $escape = null, bool $insensitiveSearch = false)
 	{
 		return $this->_like($field, $match, 'AND ', $side, 'NOT', $escape, $insensitiveSearch);
 	}
@@ -901,7 +910,7 @@ public function notLike($field, $match = '', $side = 'both', $escape = null, $in
 	 *
 	 * @return BaseBuilder
 	 */
-	public function orLike($field, $match = '', $side = 'both', $escape = null, $insensitiveSearch = false)
+	public function orLike($field, string $match = '', string $side = 'both', bool $escape = null, bool $insensitiveSearch = false)
 	{
 		return $this->_like($field, $match, 'OR ', $side, '', $escape, $insensitiveSearch);
 	}
@@ -922,7 +931,7 @@ public function orLike($field, $match = '', $side = 'both', $escape = null, $ins
 	 *
 	 * @return BaseBuilder
 	 */
-	public function orNotLike($field, $match = '', $side = 'both', $escape = null, $insensitiveSearch = false)
+	public function orNotLike($field, string $match = '', string $side = 'both', bool $escape = null, bool $insensitiveSearch = false)
 	{
 		return $this->_like($field, $match, 'OR ', $side, 'NOT', $escape, $insensitiveSearch);
 	}
@@ -947,7 +956,7 @@ public function orNotLike($field, $match = '', $side = 'both', $escape = null, $
 	 *
 	 * @return BaseBuilder
 	 */
-	protected function _like($field, $match = '', $type = 'AND ', $side = 'both', $not = '', $escape = null, $insensitiveSearch = false)
+	protected function _like($field, string $match = '', string $type = 'AND ', string $side = 'both', string $not = '', bool $escape = null, bool $insensitiveSearch = false)
 	{
 		if (! is_array($field))
 		{
@@ -1007,17 +1016,16 @@ protected function _like($field, $match = '', $type = 'AND ', $side = 'both', $n
 	/**
 	 * Platform independent LIKE statement builder.
 	 *
-	 * @param string|null $prefix
-	 * @param string      $column
-	 * @param string|null $not
-	 * @param string      $bind
-	 * @param boolean     $insensitiveSearch
+	 * @param string    $prefix
+	 * @param string    $column
+	 * @param string    $not
+	 * @param string    $bind
+	 * @param boolean   $insensitiveSearch
 	 *
 	 * @return string     $like_statement
 	 */
 	public function _like_statement(string $prefix = null, string $column, string $not = null, string $bind, bool $insensitiveSearch = false): string
 	{
-		// TODO fmertins: $column param seems to require a default value? Because $prefix has...
 		$like_statement = "{$prefix} {$column} {$not} LIKE :{$bind}:";
 
 		if ($insensitiveSearch === true)
@@ -1038,7 +1046,7 @@ public function _like_statement(string $prefix = null, string $column, string $n
 	 *
 	 * @return BaseBuilder
 	 */
-	public function groupStart($not = '', $type = 'AND ')
+	public function groupStart(string $not = '', string $type = 'AND ')
 	{
 		$type = $this->groupGetType($type);
 
@@ -1124,11 +1132,11 @@ public function groupEnd()
 	 *
 	 * @return string
 	 */
-	protected function groupGetType($type)
+	protected function groupGetType(string $type): string
 	{
 		if ($this->QBWhereGroupStarted)
 		{
-			$type                      = '';
+			$type = '';
 			$this->QBWhereGroupStarted = false;
 		}
 
@@ -1140,12 +1148,12 @@ protected function groupGetType($type)
 	/**
 	 * GROUP BY
 	 *
-	 * @param string  $by
-	 * @param boolean $escape
+	 * @param string|array  $by
+	 * @param boolean       $escape
 	 *
 	 * @return BaseBuilder
 	 */
-	public function groupBy($by, $escape = null)
+	public function groupBy($by, bool $escape = null)
 	{
 		is_bool($escape) || $escape = $this->db->protectIdentifiers;
 
@@ -1179,13 +1187,13 @@ public function groupBy($by, $escape = null)
 	 *
 	 * Separates multiple calls with 'AND'.
 	 *
-	 * @param string  $key
-	 * @param string  $value
-	 * @param boolean $escape
+	 * @param string|array  $key
+	 * @param mixed         $value
+	 * @param boolean       $escape
 	 *
 	 * @return BaseBuilder
 	 */
-	public function having($key, $value = null, $escape = null)
+	public function having($key, $value = null, bool $escape = null)
 	{
 		return $this->whereHaving('QBHaving', $key, $value, 'AND ', $escape);
 	}
@@ -1197,13 +1205,13 @@ public function having($key, $value = null, $escape = null)
 	 *
 	 * Separates multiple calls with 'OR'.
 	 *
-	 * @param string  $key
-	 * @param string  $value
-	 * @param boolean $escape
+	 * @param string|array  $key
+	 * @param mixed         $value
+	 * @param boolean       $escape
 	 *
 	 * @return BaseBuilder
 	 */
-	public function orHaving($key, $value = null, $escape = null)
+	public function orHaving($key, $value = null, bool $escape = null)
 	{
 		return $this->whereHaving('QBHaving', $key, $value, 'OR ', $escape);
 	}
@@ -1213,13 +1221,13 @@ public function orHaving($key, $value = null, $escape = null)
 	/**
 	 * ORDER BY
 	 *
-	 * @param string  $orderby
+	 * @param string  $orderBy
 	 * @param string  $direction ASC, DESC or RANDOM
 	 * @param boolean $escape
 	 *
 	 * @return BaseBuilder
 	 */
-	public function orderBy($orderby, $direction = '', $escape = null)
+	public function orderBy(string $orderBy, string $direction = '', bool $escape = null)
 	{
 		$direction = strtoupper(trim($direction));
 
@@ -1228,9 +1236,9 @@ public function orderBy($orderby, $direction = '', $escape = null)
 			$direction = '';
 
 			// Do we have a seed value?
-			$orderby = ctype_digit((string) $orderby) ? sprintf($this->randomKeyword[1], $orderby) : $this->randomKeyword[0];
+			$orderBy = ctype_digit((string) $orderBy) ? sprintf($this->randomKeyword[1], $orderBy) : $this->randomKeyword[0];
 		}
-		elseif (empty($orderby))
+		elseif (empty($orderBy))
 		{
 			return $this;
 		}
@@ -1244,7 +1252,7 @@ public function orderBy($orderby, $direction = '', $escape = null)
 		if ($escape === false)
 		{
 			$qb_orderby[] = [
-				'field'     => $orderby,
+				'field'     => $orderBy,
 				'direction' => $direction,
 				'escape'    => false,
 			];
@@ -1252,18 +1260,21 @@ public function orderBy($orderby, $direction = '', $escape = null)
 		else
 		{
 			$qb_orderby = [];
-			foreach (explode(',', $orderby) as $field)
+			foreach (explode(',', $orderBy) as $field)
 			{
-				$qb_orderby[] = ($direction === '' &&
-						preg_match('/\s+(ASC|DESC)$/i', rtrim($field), $match, PREG_OFFSET_CAPTURE)) ? [
-																										   'field'     => ltrim(substr($field, 0, $match[0][1])),
-																										   'direction' => ' ' . $match[1][0],
-																										   'escape'    => true,
-																									   ] : [
-																											   'field'     => trim($field),
-																											   'direction' => $direction,
-																											   'escape'    => true,
-																										   ];
+				$qb_orderby[] = ($direction === '' && preg_match('/\s+(ASC|DESC)$/i', rtrim($field), $match, PREG_OFFSET_CAPTURE))
+					?
+					[
+						'field'     => ltrim(substr($field, 0, $match[0][1])),
+						'direction' => ' ' . $match[1][0],
+						'escape'    => true,
+					]
+					:
+					[
+						'field'     => trim($field),
+						'direction' => $direction,
+						'escape'    => true,
+					];
 			}
 		}
 
@@ -1306,7 +1317,7 @@ public function limit(int $value = null, int $offset = 0)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function offset($offset)
+	public function offset(int $offset)
 	{
 		if (! empty($offset))
 		{
@@ -1327,7 +1338,7 @@ public function offset($offset)
 	 *
 	 * @return string
 	 */
-	protected function _limit($sql)
+	protected function _limit(string $sql): string
 	{
 		return $sql . ' LIMIT ' . ($this->QBOffset ? $this->QBOffset . ', ' : '') . $this->QBLimit;
 	}
@@ -1345,7 +1356,7 @@ protected function _limit($sql)
 	 *
 	 * @return BaseBuilder
 	 */
-	public function set($key, $value = '', $escape = null)
+	public function set($key, string $value = '', bool $escape = null)
 	{
 		$key = $this->objectToArray($key);
 
@@ -1360,7 +1371,7 @@ public function set($key, $value = '', $escape = null)
 		{
 			if ($escape)
 			{
-				$bind                                                           = $this->setBind($k, $v, $escape);
+				$bind = $this->setBind($k, $v, $escape);
 				$this->QBSet[$this->db->protectIdentifiers($k, false, $escape)] = ":$bind:";
 			}
 			else
@@ -1382,7 +1393,7 @@ public function set($key, $value = '', $escape = null)
 	 *
 	 * @return array
 	 */
-	public function getSetData(bool $clean = false)
+	public function getSetData(bool $clean = false): array
 	{
 		$data = $this->QBSet;
 
@@ -1405,7 +1416,7 @@ public function getSetData(bool $clean = false)
 	 *
 	 * @return string
 	 */
-	public function getCompiledSelect($reset = true)
+	public function getCompiledSelect(bool $reset = true): string
 	{
 		$select = $this->compileSelect();
 
@@ -1425,7 +1436,7 @@ public function getCompiledSelect($reset = true)
 	 *
 	 * @param string $sql
 	 *
-	 * @return mixed|string
+	 * @return string
 	 */
 	protected function compileFinalQuery(string $sql): string
 	{
@@ -1453,7 +1464,7 @@ protected function compileFinalQuery(string $sql): string
 	 *
 	 * @return ResultInterface
 	 */
-	public function get(int $limit = null, int $offset = 0, $returnSQL = false, $reset = true)
+	public function get(int $limit = null, int $offset = 0, bool $returnSQL = false, bool $reset = true)
 	{
 		if (! is_null($limit))
 		{
@@ -1486,9 +1497,9 @@ public function get(int $limit = null, int $offset = 0, $returnSQL = false, $res
 	 * @param boolean $reset Are we want to clear query builder values?
 	 * @param boolean $test  Are we running automated tests?
 	 *
-	 * @return integer
+	 * @return integer|string when $test = true
 	 */
-	public function countAll($reset = true, $test = false)
+	public function countAll(bool $reset = true, bool $test = false)
 	{
 		$table = $this->QBFrom[0];
 
@@ -1527,22 +1538,25 @@ public function countAll($reset = true, $test = false)
 	 * @param boolean $reset
 	 * @param boolean $test  The reset clause
 	 *
-	 * @return integer
+	 * @return integer|string when $test = true
 	 */
-	public function countAllResults($reset = true, $test = false)
+	public function countAllResults(bool $reset = true, bool $test = false)
 	{
 		// ORDER BY usage is often problematic here (most notably
 		// on Microsoft SQL Server) and ultimately unnecessary
 		// for selecting COUNT(*) ...
-		$orderby = [];
+		$orderBy = [];
 		if (! empty($this->QBOrderBy))
 		{
-			$orderby         = $this->QBOrderBy;
+			$orderBy         = $this->QBOrderBy;
 			$this->QBOrderBy = null;
 		}
 
-		$sql = ($this->QBDistinct === true) ? $this->countString . $this->db->protectIdentifiers('numrows') . "\nFROM (\n" .
-				$this->compileSelect() . "\n) CI_count_all_results" : $this->compileSelect($this->countString . $this->db->protectIdentifiers('numrows'));
+		$sql = ($this->QBDistinct === true)
+			?
+			$this->countString . $this->db->protectIdentifiers('numrows') . "\nFROM (\n" . $this->compileSelect() . "\n) CI_count_all_results"
+			:
+			$this->compileSelect($this->countString . $this->db->protectIdentifiers('numrows'));
 
 		if ($test)
 		{
@@ -1558,7 +1572,7 @@ public function countAllResults($reset = true, $test = false)
 		// If we've previously reset the QBOrderBy values, get them back
 		elseif (! isset($this->QBOrderBy))
 		{
-			$this->QBOrderBy = $orderby ?? [];
+			$this->QBOrderBy = $orderBy ?? [];
 		}
 
 		$row = (! $result instanceof ResultInterface)
@@ -1580,13 +1594,13 @@ public function countAllResults($reset = true, $test = false)
 	 *
 	 * Allows the where clause, limit and offset to be added directly
 	 *
-	 * @param string  $where
-	 * @param integer $limit
-	 * @param integer $offset
+	 * @param string|array  $where
+	 * @param integer       $limit
+	 * @param integer       $offset
 	 *
 	 * @return ResultInterface
 	 */
-	public function getWhere($where = null, $limit = null, $offset = null)
+	public function getWhere($where = null, int $limit = null, int $offset = null)
 	{
 		if ($where !== null)
 		{
@@ -1620,7 +1634,7 @@ public function getWhere($where = null, $limit = null, $offset = null)
 	 * @return integer Number of rows inserted or FALSE on failure
 	 * @throws DatabaseException
 	 */
-	public function insertBatch($set = null, $escape = null, $batchSize = 100, $testing = false)
+	public function insertBatch(array $set = null, bool $escape = null, int $batchSize = 100, bool $testing = false)
 	{
 		if ($set === null)
 		{
@@ -1689,7 +1703,7 @@ public function insertBatch($set = null, $escape = null, $batchSize = 100, $test
 	 *
 	 * @return string
 	 */
-	protected function _insertBatch($table, $keys, $values)
+	protected function _insertBatch(string $table, array $keys, array $values): string
 	{
 		return 'INSERT INTO ' . $table . ' (' . implode(', ', $keys) . ') VALUES ' . implode(', ', $values);
 	}
@@ -1703,9 +1717,9 @@ protected function _insertBatch($table, $keys, $values)
 	 * @param string  $value
 	 * @param boolean $escape
 	 *
-	 * @return BaseBuilder
+	 * @return BaseBuilder|null
 	 */
-	public function setInsertBatch($key, $value = '', $escape = null)
+	public function setInsertBatch($key, string $value = '', bool $escape = null)
 	{
 		$key = $this->batchObjectToArray($key);
 
@@ -1727,7 +1741,7 @@ public function setInsertBatch($key, $value = '', $escape = null)
 				// batch function above returns an error on an empty array
 				$this->QBSet[] = [];
 
-				return;
+				return null;
 			}
 
 			ksort($row); // puts $row in the same order as our keys
@@ -1762,7 +1776,7 @@ public function setInsertBatch($key, $value = '', $escape = null)
 	 *
 	 * @return string
 	 */
-	public function getCompiledInsert($reset = true)
+	public function getCompiledInsert(bool $reset = true): string
 	{
 		if ($this->validateInsert() === false)
 		{
@@ -1796,7 +1810,7 @@ public function getCompiledInsert($reset = true)
 	 *
 	 * @return BaseResult|Query|false
 	 */
-	public function insert($set = null, $escape = null, $test = false)
+	public function insert(array $set = null, bool $escape = null, bool $test = false)
 	{
 		if ($set !== null)
 		{
@@ -1825,6 +1839,8 @@ public function insert($set = null, $escape = null, $test = false)
 
 			return $result;
 		}
+
+		return false;
 	}
 
 	//--------------------------------------------------------------------
@@ -1836,10 +1852,10 @@ public function insert($set = null, $escape = null, $test = false)
 	 * validate that the there data is actually being set and that table
 	 * has been chosen to be inserted into.
 	 *
-	 * @return string
+	 * @return bool
 	 * @throws DatabaseException
 	 */
-	protected function validateInsert()
+	protected function validateInsert(): bool
 	{
 		if (empty($this->QBSet))
 		{
@@ -1867,7 +1883,7 @@ protected function validateInsert()
 	 *
 	 * @return string
 	 */
-	protected function _insert($table, array $keys, array $unescapedKeys)
+	protected function _insert(string $table, array $keys, array $unescapedKeys): string
 	{
 		return 'INSERT INTO ' . $table . ' (' . implode(', ', $keys) . ') VALUES (' . implode(', ', $unescapedKeys) . ')';
 	}
@@ -1885,7 +1901,7 @@ protected function _insert($table, array $keys, array $unescapedKeys)
 	 * @return BaseResult|Query|string|false
 	 * @throws DatabaseException
 	 */
-	public function replace($set = null, $returnSQL = false)
+	public function replace(array $set = null, bool $returnSQL = false)
 	{
 		if ($set !== null)
 		{
@@ -1923,7 +1939,7 @@ public function replace($set = null, $returnSQL = false)
 	 *
 	 * @return string
 	 */
-	protected function _replace($table, $keys, $values)
+	protected function _replace(string $table, array $keys, array $values): string
 	{
 		return 'REPLACE INTO ' . $table . ' (' . implode(', ', $keys) . ') VALUES (' . implode(', ', $values) . ')';
 	}
@@ -1940,7 +1956,7 @@ protected function _replace($table, $keys, $values)
 	 *
 	 * @return string
 	 */
-	protected function _fromTables()
+	protected function _fromTables(): string
 	{
 		return implode(', ', $this->QBFrom);
 	}
@@ -1956,7 +1972,7 @@ protected function _fromTables()
 	 *
 	 * @return string
 	 */
-	public function getCompiledUpdate($reset = true)
+	public function getCompiledUpdate(bool $reset = true): string
 	{
 		if ($this->validateUpdate() === false)
 		{
@@ -1987,7 +2003,7 @@ public function getCompiledUpdate($reset = true)
 	 *
 	 * @return boolean    TRUE on success, FALSE on failure
 	 */
-	public function update($set = null, $where = null, int $limit = null, $test = false)
+	public function update(array $set = null, $where = null, int $limit = null, bool $test = false): bool
 	{
 		if ($set !== null)
 		{
@@ -2046,8 +2062,10 @@ public function update($set = null, $where = null, int $limit = null, $test = fa
 	 *
 	 * @return string
 	 */
-	protected function _update($table, $values)
+	protected function _update(string $table, array $values): string
 	{
+		$valstr = [];
+
 		foreach ($values as $key => $val)
 		{
 			$valstr[] = $key . ' = ' . $val;
@@ -2071,7 +2089,7 @@ protected function _update($table, $values)
 	 * @return boolean
 	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
 	 */
-	protected function validateUpdate()
+	protected function validateUpdate(): bool
 	{
 		if (empty($this->QBSet))
 		{
@@ -2101,7 +2119,7 @@ protected function validateUpdate()
 	 * @return mixed    Number of rows affected, SQL string, or FALSE on failure
 	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
 	 */
-	public function updateBatch($set = null, $index = null, $batchSize = 100, $returnSQL = false)
+	public function updateBatch(array $set = null, string $index = null, int $batchSize = 100, bool $returnSQL = false)
 	{
 		if ($index === null)
 		{
@@ -2142,7 +2160,7 @@ public function updateBatch($set = null, $index = null, $batchSize = 100, $retur
 
 		// Batch this baby
 		$affected_rows = 0;
-		$savedSQL      = [];
+		$savedSQL = [];
 		for ($i = 0, $total = count($this->QBSet); $i < $total; $i += $batchSize)
 		{
 			$sql = $this->_updateBatch($table, array_slice($this->QBSet, $i, $batchSize), $this->db->protectIdentifiers($index)
@@ -2179,9 +2197,10 @@ public function updateBatch($set = null, $index = null, $batchSize = 100, $retur
 	 *
 	 * @return string
 	 */
-	protected function _updateBatch($table, $values, $index)
+	protected function _updateBatch(string $table, array $values, string $index): string
 	{
 		$ids = [];
+		$final = [];
 		foreach ($values as $key => $val)
 		{
 			$ids[] = $val[$index];
@@ -2213,20 +2232,20 @@ protected function _updateBatch($table, $values, $index)
 	/**
 	 * The "setUpdateBatch" function.  Allows key/value pairs to be set for batch updating
 	 *
-	 * @param array   $key
-	 * @param string  $index
-	 * @param boolean $escape
+	 * @param array|object   $key
+	 * @param string         $index
+	 * @param boolean        $escape
 	 *
-	 * @return BaseBuilder
+	 * @return BaseBuilder|null
 	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
 	 */
-	public function setUpdateBatch($key, $index = '', $escape = null)
+	public function setUpdateBatch($key, string $index = '', bool $escape = null)
 	{
 		$key = $this->batchObjectToArray($key);
 
 		if (! is_array($key))
 		{
-			return;
+			return null;
 		}
 
 		is_bool($escape) || $escape = $this->db->protectIdentifiers;
@@ -2268,7 +2287,7 @@ public function setUpdateBatch($key, $index = '', $escape = null)
 	 * @param  boolean $test
 	 * @return boolean    TRUE on success, FALSE on failure
 	 */
-	public function emptyTable($test = false)
+	public function emptyTable(bool $test = false)
 	{
 		$table = $this->QBFrom[0];
 
@@ -2297,7 +2316,7 @@ public function emptyTable($test = false)
 	 *
 	 * @return boolean    TRUE on success, FALSE on failure
 	 */
-	public function truncate($test = false)
+	public function truncate(bool $test = false)
 	{
 		$table = $this->QBFrom[0];
 
@@ -2327,7 +2346,7 @@ public function truncate($test = false)
 	 *
 	 * @return string
 	 */
-	protected function _truncate($table)
+	protected function _truncate(string $table): string
 	{
 		return 'TRUNCATE ' . $table;
 	}
@@ -2343,13 +2362,11 @@ protected function _truncate($table)
 	 *
 	 * @return string
 	 */
-	public function getCompiledDelete($reset = true)
+	public function getCompiledDelete(bool $reset = true): string
 	{
 		$table = $this->QBFrom[0];
 
-		$this->returnDeleteSQL = true;
-		$sql                   = $this->delete($table, '', null, $reset);
-		$this->returnDeleteSQL = false;
+		$sql = $this->delete($table, '', $reset, true);
 
 		return $this->compileFinalQuery($sql);
 	}
@@ -2362,14 +2379,14 @@ public function getCompiledDelete($reset = true)
 	 * Compiles a delete string and runs the query
 	 *
 	 * @param mixed   $where      The where clause
-	 * @param mixed   $limit      The limit clause
+	 * @param integer $limit      The limit clause
 	 * @param boolean $reset_data
 	 * @param boolean $returnSQL
 	 *
 	 * @return mixed
 	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
 	 */
-	public function delete($where = '', $limit = null, $reset_data = true, $returnSQL = false)
+	public function delete($where = '', int $limit = null, bool $reset_data = true, bool $returnSQL = false)
 	{
 		$table = $this->db->protectIdentifiers($this->QBFrom[0], true, null, false);
 
@@ -2462,7 +2479,7 @@ public function decrement(string $column, int $value = 1)
 	 *
 	 * @return string
 	 */
-	protected function _delete($table)
+	protected function _delete(string $table): string
 	{
 		return 'DELETE FROM ' . $table . $this->compileWhereHaving('QBWhere')
 				. ($this->QBLimit ? ' LIMIT ' . $this->QBLimit : '');
@@ -2475,9 +2492,9 @@ protected function _delete($table)
 	 *
 	 * Used to track SQL statements written with aliased tables.
 	 *
-	 * @param string $table The table to inspect
+	 * @param string|array $table The table to inspect
 	 *
-	 * @return string
+	 * @return string|void
 	 */
 	protected function trackAliases($table)
 	{
@@ -2487,8 +2504,6 @@ protected function trackAliases($table)
 			{
 				$this->trackAliases($t);
 			}
-
-			return;
 		}
 
 		// Does the string contain a comma?  If so, we need to separate
@@ -2520,11 +2535,11 @@ protected function trackAliases($table)
 	 * Generates a query string based on which functions were used.
 	 * Should not be called directly.
 	 *
-	 * @param boolean $select_override
+	 * @param mixed $select_override
 	 *
 	 * @return string
 	 */
-	protected function compileSelect($select_override = false)
+	protected function compileSelect($select_override = false): string
 	{
 		// Write the "select" portion of the query
 		if ($select_override !== false)
@@ -2594,7 +2609,7 @@ protected function compileSelect($select_override = false)
 	 *
 	 * @return string    SQL statement
 	 */
-	protected function compileWhereHaving($qb_key)
+	protected function compileWhereHaving(string $qb_key): string
 	{
 		if (! empty($this->$qb_key))
 		{
@@ -2636,7 +2651,6 @@ protected function compileWhereHaving($qb_key)
 
 					if (! empty($matches[4]))
 					{
-						//                      $this->isLiteral($matches[4]) OR $matches[4] = $this->db->protectIdentifiers(trim($matches[4]));
 						$matches[4] = ' ' . $matches[4];
 					}
 
@@ -2667,7 +2681,7 @@ protected function compileWhereHaving($qb_key)
 	 *
 	 * @return string    SQL statement
 	 */
-	protected function compileGroupBy()
+	protected function compileGroupBy(): string
 	{
 		if (! empty($this->QBGroupBy))
 		{
@@ -2702,7 +2716,7 @@ protected function compileGroupBy()
 	 *
 	 * @return string    SQL statement
 	 */
-	protected function compileOrderBy()
+	protected function compileOrderBy(): string
 	{
 		if (is_array($this->QBOrderBy) && ! empty($this->QBOrderBy))
 		{
@@ -2733,9 +2747,9 @@ protected function compileOrderBy()
 	 *
 	 * Takes an object as input and converts the class variables to array key/vals
 	 *
-	 * @param object $object
+	 * @param mixed $object
 	 *
-	 * @return array
+	 * @return mixed
 	 */
 	protected function objectToArray($object)
 	{
@@ -2764,9 +2778,9 @@ protected function objectToArray($object)
 	 *
 	 * Takes an object as input and converts the class variables to array key/vals
 	 *
-	 * @param object $object
+	 * @param mixed $object
 	 *
-	 * @return array
+	 * @return mixed
 	 */
 	protected function batchObjectToArray($object)
 	{
@@ -2806,7 +2820,7 @@ protected function batchObjectToArray($object)
 	 *
 	 * @return boolean
 	 */
-	protected function isLiteral($str)
+	protected function isLiteral(string $str): bool
 	{
 		$str = trim($str);
 
@@ -2850,8 +2864,10 @@ public function resetQuery()
 	 * Resets the query builder values.  Called by the get() function
 	 *
 	 * @param array $qb_reset_items An array of fields to reset
+	 *
+	 * @return void
 	 */
-	protected function resetRun($qb_reset_items)
+	protected function resetRun(array $qb_reset_items)
 	{
 		foreach ($qb_reset_items as $item => $default_value)
 		{
@@ -2913,7 +2929,7 @@ protected function resetWrite()
 	 *
 	 * @return boolean
 	 */
-	protected function hasOperator($str)
+	protected function hasOperator(string $str): bool
 	{
 		return (bool) preg_match('/(<|>|!|=|\sIS NULL|\sIS NOT NULL|\sEXISTS|\sBETWEEN|\sLIKE|\sIN\s*\(|\s)/i', trim($str));
 	}
@@ -2926,9 +2942,9 @@ protected function hasOperator($str)
 	 * @param string  $str
 	 * @param boolean $list
 	 *
-	 * @return string
+	 * @return mixed
 	 */
-	protected function getOperator($str, bool $list = false)
+	protected function getOperator(string $str, bool $list = false)
 	{
 		static $_operators;
 
@@ -2963,12 +2979,12 @@ protected function getOperator($str, bool $list = false)
 	 * arrays instead, so lets take advantage of that here.
 	 *
 	 * @param string  $key
-	 * @param null    $value
+	 * @param mixed   $value
 	 * @param boolean $escape
 	 *
 	 * @return string
 	 */
-	protected function setBind(string $key, $value = null, bool $escape = true)
+	protected function setBind(string $key, $value = null, bool $escape = true): string
 	{
 		if (! array_key_exists($key, $this->binds))
 		{
diff --git a/system/Database/Exceptions/DataException.php b/system/Database/Exceptions/DataException.php
index 7230eca20493..966c6ef43f6f 100644
--- a/system/Database/Exceptions/DataException.php
+++ b/system/Database/Exceptions/DataException.php
@@ -51,6 +51,12 @@ public static function forTableNotFound(string $table)
 		return new static(lang('Database.tableNotFound', [$table]));
 	}
 
+
+	public static function forEmptyInputGiven(string $argument)
+	{
+		return new static(lang('Database.forEmptyInputGiven', [$argument]));
+  }
+  
 	public static function forFindColumnHaveMultipleColumns()
 	{
 		return new static(lang('Database.forFindColumnHaveMultipleColumns'));
diff --git a/system/Database/Postgre/Builder.php b/system/Database/Postgre/Builder.php
index 2de81cb63bd5..7ab065aa9992 100644
--- a/system/Database/Postgre/Builder.php
+++ b/system/Database/Postgre/Builder.php
@@ -61,33 +61,33 @@ class Builder extends BaseBuilder
 	/**
 	 * ORDER BY
 	 *
-	 * @param string  $orderby
+	 * @param string  $orderBy
 	 * @param string  $direction ASC, DESC or RANDOM
 	 * @param boolean $escape
 	 *
 	 * @return BaseBuilder
 	 */
-	public function orderBy($orderby, $direction = '', $escape = null)
+	public function orderBy(string $orderBy, string $direction = '', bool $escape = null)
 	{
 		$direction = strtoupper(trim($direction));
 		if ($direction === 'RANDOM')
 		{
-			if (! is_float($orderby) && ctype_digit((string) $orderby))
+			if (! is_float($orderBy) && ctype_digit((string) $orderBy))
 			{
-				$orderby = (float) ($orderby > 1 ? "0.{$orderby}" : $orderby);
+				$orderBy = (float) ($orderBy > 1 ? "0.{$orderBy}" : $orderBy);
 			}
 
-			if (is_float($orderby))
+			if (is_float($orderBy))
 			{
-				$this->db->simpleQuery("SET SEED {$orderby}");
+				$this->db->simpleQuery("SET SEED {$orderBy}");
 			}
 
-			$orderby   = $this->randomKeyword[0];
+			$orderBy   = $this->randomKeyword[0];
 			$direction = '';
 			$escape    = false;
 		}
 
-		return parent::orderBy($orderby, $direction, $escape);
+		return parent::orderBy($orderBy, $direction, $escape);
 	}
 
 	//--------------------------------------------------------------------
@@ -145,7 +145,7 @@ public function decrement(string $column, int $value = 1)
 	 * @throws   DatabaseException
 	 * @internal param true $bool returns the generated SQL, false executes the query.
 	 */
-	public function replace($set = null, $returnSQL = false)
+	public function replace(array $set = null, bool $returnSQL = false)
 	{
 		if ($set !== null)
 		{
@@ -200,8 +200,8 @@ public function replace($set = null, $returnSQL = false)
 	 *
 	 * Compiles a delete string and runs the query
 	 *
-	 * @param string  $where
-	 * @param null    $limit
+	 * @param mixed   $where
+	 * @param integer $limit
 	 * @param boolean $reset_data
 	 * @param boolean $returnSQL
 	 *
@@ -211,7 +211,7 @@ public function replace($set = null, $returnSQL = false)
 	 * @internal param the $mixed limit clause
 	 * @internal param $bool
 	 */
-	public function delete($where = '', $limit = null, $reset_data = true, $returnSQL = false)
+	public function delete($where = '', int $limit = null, bool $reset_data = true, bool $returnSQL = false)
 	{
 		if (! empty($limit) || ! empty($this->QBLimit))
 		{
@@ -232,7 +232,7 @@ public function delete($where = '', $limit = null, $reset_data = true, $returnSQ
 	 *
 	 * @return string
 	 */
-	protected function _limit($sql)
+	protected function _limit(string $sql): string
 	{
 		return $sql . ' LIMIT ' . $this->QBLimit . ($this->QBOffset ? " OFFSET {$this->QBOffset}" : '');
 	}
@@ -252,7 +252,7 @@ protected function _limit($sql)
 	 * @internal param the $string table name
 	 * @internal param the $array update data
 	 */
-	protected function _update($table, $values)
+	protected function _update(string $table, array $values): string
 	{
 		if (! empty($this->QBLimit))
 		{
@@ -276,7 +276,7 @@ protected function _update($table, $values)
 	 *
 	 * @return string
 	 */
-	protected function _updateBatch($table, $values, $index)
+	protected function _updateBatch(string $table, array $values, string $index): string
 	{
 		$ids = [];
 		foreach ($values as $key => $val)
@@ -316,7 +316,7 @@ protected function _updateBatch($table, $values, $index)
 	 *
 	 * @return string
 	 */
-	protected function _delete($table)
+	protected function _delete(string $table): string
 	{
 		$this->QBLimit = false;
 		return parent::_delete($table);
@@ -336,7 +336,7 @@ protected function _delete($table)
 	 *
 	 * @return string
 	 */
-	protected function _truncate($table)
+	protected function _truncate(string $table): string
 	{
 		return 'TRUNCATE ' . $table . ' RESTART IDENTITY';
 	}
@@ -351,11 +351,11 @@ protected function _truncate($table)
 	 *
 	 * @see https://www.postgresql.org/docs/9.2/static/functions-matching.html
 	 *
-	 * @param string|null $prefix
-	 * @param string      $column
-	 * @param string|null $not
-	 * @param string      $bind
-	 * @param boolean     $insensitiveSearch
+	 * @param string    $prefix
+	 * @param string    $column
+	 * @param string    $not
+	 * @param string    $bind
+	 * @param boolean   $insensitiveSearch
 	 *
 	 * @return string     $like_statement
 	 */
diff --git a/system/Database/SQLite3/Builder.php b/system/Database/SQLite3/Builder.php
index 11f9d7ec2dbe..4d1c84e213e6 100644
--- a/system/Database/SQLite3/Builder.php
+++ b/system/Database/SQLite3/Builder.php
@@ -82,7 +82,7 @@ class Builder extends BaseBuilder
 	 *
 	 * @return string
 	 */
-	protected function _replace($table, $keys, $values)
+	protected function _replace(string $table, array $keys, array $values): string
 	{
 		return 'INSERT OR ' . parent::_replace($table, $keys, $values);
 	}
@@ -100,7 +100,7 @@ protected function _replace($table, $keys, $values)
 	 * @param  string $table
 	 * @return string
 	 */
-	protected function _truncate($table)
+	protected function _truncate(string $table): string
 	{
 		return 'DELETE FROM ' . $table;
 	}
diff --git a/system/Language/en/Database.php b/system/Language/en/Database.php
index 8f8149f2c982..9afce1863724 100644
--- a/system/Language/en/Database.php
+++ b/system/Language/en/Database.php
@@ -26,5 +26,6 @@
 	'featureUnavailable'               => 'This feature is not available for the database you are using.',
 	'tableNotFound'                    => 'Table `{0}` was not found in the current database.',
 	'noPrimaryKey'                     => '`{0}` model class does not specify a Primary Key.',
+  'forEmptyInputGiven'               => 'Empty statement is given for the field `{0}`',
 	'forFindColumnHaveMultipleColumns' => 'Only single column allowed in Column name.',
 ];
diff --git a/tests/system/Database/Builder/EmptyTest.php b/tests/system/Database/Builder/EmptyTest.php
index 1720ce76549b..835ab3fbcd86 100644
--- a/tests/system/Database/Builder/EmptyTest.php
+++ b/tests/system/Database/Builder/EmptyTest.php
@@ -20,8 +20,7 @@ protected function setUp()
 
 	public function testEmptyWithNoTable()
 	{
-		$builder                  = new BaseBuilder('jobs', $this->db);
-		$builder->returnDeleteSQL = true;
+		$builder = new BaseBuilder('jobs', $this->db);
 
 		$answer = $builder->emptyTable(true);
 
diff --git a/tests/system/Database/Builder/SelectTest.php b/tests/system/Database/Builder/SelectTest.php
index 58fe22f22867..1623149e7317 100644
--- a/tests/system/Database/Builder/SelectTest.php
+++ b/tests/system/Database/Builder/SelectTest.php
@@ -1,6 +1,7 @@
 <?php namespace CodeIgniter\Database\Builder;
 
 use CodeIgniter\Database\BaseBuilder;
+use CodeIgniter\Database\Exceptions\DataException;
 use Tests\Support\Database\MockConnection;
 
 class SelectTest extends \CIUnitTestCase
@@ -202,8 +203,8 @@ public function testSelectMinThrowsExceptionOnEmptyValue()
 	{
 		$builder = new BaseBuilder('invoices', $this->db);
 
-		$this->expectException('\CodeIgniter\Database\Exceptions\DatabaseException');
-		$this->expectExceptionMessage('The query you submitted is not valid.');
+		$this->expectException(DataException::class);
+		$this->expectExceptionMessage('Empty statement is given for the field `Select`');
 
 		$builder->selectSum('');
 	}
@@ -222,4 +223,17 @@ public function testSelectMaxWithDotNameAndNoAlias()
 	}
 
 	//--------------------------------------------------------------------
+
+	public function testSelectMinThrowsExceptionOnMultipleColumn()
+	{
+		$builder = new BaseBuilder('users', $this->db);
+
+		$this->expectException(DataException::class);
+		$this->expectExceptionMessage('You must provide a valid column name not separated by comma.');
+
+		$builder->selectSum('name,role');
+	}
+
+	//--------------------------------------------------------------------
+
 }