Specialize Postgres integer JDBC interactions

The Postgres JDBC driver and wire protocol treat varying integer sizes differently. For example, an Int only transfers 4 bytes, while Long transfers the full 8. Since we have the ability to call the proper JDBC methods, we should do so.

dialects/postgresql/src/main/kotlin/app/cash/sqldelight/dialects/postgresql/PostgreSqlType.kt

@@ -12,12 +12,12 @@ internal enum class PostgreSqlType(override val javaType: TypeName) : DialectTyp
   SMALL_INT(SHORT) {
     override fun decode(value: CodeBlock) = CodeBlock.of("%L.toShort()", value)
 
-    override fun encode(value: CodeBlock) = CodeBlock.of("%L.toLong()", value)
+    override fun encode(value: CodeBlock) = CodeBlock.of("%L.toShort()", value)
   },
   INTEGER(INT) {
     override fun decode(value: CodeBlock) = CodeBlock.of("%L.toInt()", value)
 
-    override fun encode(value: CodeBlock) = CodeBlock.of("%L.toLong()", value)
+    override fun encode(value: CodeBlock) = CodeBlock.of("%L.toInt()", value)
   },
   BIG_INT(LONG),
   DATE(ClassName("java.time", "LocalDate")),
@@ -33,7 +33,9 @@ internal enum class PostgreSqlType(override val javaType: TypeName) : DialectTyp
     return CodeBlock.builder()
       .add(
         when (this) {
-          SMALL_INT, INTEGER, BIG_INT -> "bindLong"
+          SMALL_INT -> "bindShort"
+          INTEGER -> "bindInt"
+          BIG_INT -> "bindLong"
           DATE, TIME, TIMESTAMP, TIMESTAMP_TIMEZONE, INTERVAL, UUID -> "bindObject"
           NUMERIC -> "bindBigDecimal"
         },
@@ -45,7 +47,9 @@ internal enum class PostgreSqlType(override val javaType: TypeName) : DialectTyp
   override fun cursorGetter(columnIndex: Int, cursorName: String): CodeBlock {
     return CodeBlock.of(
       when (this) {
-        SMALL_INT, INTEGER, BIG_INT -> "$cursorName.getLong($columnIndex)"
+        SMALL_INT -> "$cursorName.getShort($columnIndex)"
+        INTEGER -> "$cursorName.getInt($columnIndex)"
+        BIG_INT -> "$cursorName.getLong($columnIndex)"
         DATE, TIME, TIMESTAMP, TIMESTAMP_TIMEZONE, INTERVAL, UUID -> "$cursorName.getObject<%T>($columnIndex)"
         NUMERIC -> "$cursorName.getBigDecimal($columnIndex)"
       },