Add postgreSql character length functions

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

@@ -89,6 +89,7 @@ class PostgreSqlTypeResolver(private val parentResolver: TypeResolver) : TypeRes
     "date_trunc" -> encapsulatingType(exprList, TIMESTAMP_TIMEZONE, TIMESTAMP)
     "now" -> IntermediateType(TIMESTAMP_TIMEZONE)
     "gen_random_uuid" -> IntermediateType(PostgreSqlType.UUID)
+    "length", "character_length", "char_length" -> IntermediateType(PostgreSqlType.INTEGER).nullableIf(resolvedType(exprList[0]).javaType.isNullable)
     else -> null
   }
 

dialects/postgresql/src/test/fixtures_postgresql/alter-table-add-constraint-check/1.s

@@ -1,6 +1,12 @@
 CREATE TABLE t1 (
-  c1 INTEGER
+  c1 INTEGER,
+  t1 TEXT,
+  t2 VARCHAR(255),
+  t3 CHAR(10)
 );
 
 ALTER TABLE t1
- ADD CONSTRAINT chk_c1 CHECK (c1 > 0);
+  ADD CONSTRAINT chk_c1 CHECK (c1 > 0),
+  ADD CONSTRAINT chk_t1 CHECK (LENGTH(t1) > 0),
+  ADD CONSTRAINT chk_t2 CHECK (CHAR_LENGTH(t2) > 0),
+  ADD CONSTRAINT chk_t3 CHECK (CHARACTER_LENGTH(t3) > 0);

sqldelight-gradle-plugin/src/test/integration-postgresql/src/main/sqldelight/app/cash/sqldelight/postgresql/integration/Characters.sq

@@ -0,0 +1,13 @@
+CREATE TABLE characters(
+  name TEXT NOT NULL,
+  description TEXT
+);
+
+insertCharacter:
+  INSERT INTO characters (name, description) VALUES (:name, :description);
+
+selectNameLength:
+  SELECT length(name) FROM characters;
+
+selectDescriptionLength:
+  SELECT length(description) FROM characters;

sqldelight-gradle-plugin/src/test/integration-postgresql/src/test/kotlin/app/cash/sqldelight/postgresql/integration/PostgreSqlTest.kt

@@ -271,4 +271,12 @@ class PostgreSqlTest {
     val uuid: UUID = database.uuidsQueries.randomUuid().executeAsOne()
     assertThat(uuid).isNotNull()
   }
+
+  @Test fun lengthFunction() {
+    database.charactersQueries.insertCharacter("abcdef", null)
+    val name = database.charactersQueries.selectNameLength().executeAsOne()
+    assertThat(name).isEqualTo(6)
+    val desc = database.charactersQueries.selectDescriptionLength().executeAsOne()
+    assertThat(desc.length).isNull()
+  }
 }