Implement DROP CONSTRAINT for CHECK constraints

Author: JanJakes

tests/WP_SQLite_Driver_Tests.php

@@ -9177,4 +9177,24 @@ public function testAlterTableAddCheckConstraint(): void {
 		$this->expectExceptionMessage( 'SQLSTATE[23000]: Integrity constraint violation: 19 CHECK constraint failed: c' );
 		$this->assertQuery( 'INSERT INTO t (id) VALUES (0)' );
 	}
+
+	public function testAlterTableDropCheckConstraint(): void {
+		$this->assertQuery( 'CREATE TABLE t (id INT, CONSTRAINT c CHECK (id > 0))' );
+		$this->assertQuery( 'ALTER TABLE t DROP CONSTRAINT c' );
+
+		// SHOW CREATE TABLE
+		$this->assertQuery( 'SHOW CREATE TABLE t' );
+		$result = $this->engine->get_query_results();
+		$this->assertEquals(
+			implode(
+				"\n",
+				array(
+					'CREATE TABLE `t` (',
+					'  `id` int DEFAULT NULL',
+					') ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci',
+				)
+			),
+			$result[0]->{'Create Table'}
+		);
+	}
 }

wp-includes/sqlite-ast/class-wp-sqlite-information-schema-builder.php

@@ -1301,6 +1301,8 @@ private function record_drop_constraint(
 			$this->record_drop_key( $table_is_temporary, $table_name, $name );
 		} elseif ( 'FOREIGN KEY' === $constraint_type ) {
 			$this->record_drop_foreign_key( $table_is_temporary, $table_name, $name );
+		} elseif ( 'CHECK' === $constraint_type ) {
+			$this->record_drop_check_constraint( $table_is_temporary, $table_name, $name );
 		} else {
 			throw new \Exception(
 				"DROP CONSTRAINT for constraint type '$constraint_type' is not supported."
@@ -1398,6 +1400,37 @@ private function record_drop_foreign_key(
 		);
 	}
 
+	/**
+	 * Analyze DROP CHECK statement and record data in the information schema.
+	 *
+	 * @param bool   $table_is_temporary Whether the table is temporary.
+	 * @param string $table_name         The table name.
+	 * @param string $name               The check constraint name.
+	 */
+	private function record_drop_check_constraint(
+		bool $table_is_temporary,
+		string $table_name,
+		string $name
+	): void {
+		$this->delete_values(
+			$this->get_table_name( $table_is_temporary, 'table_constraints' ),
+			array(
+				'CONSTRAINT_SCHEMA' => $this->db_name,
+				'TABLE_NAME'        => $table_name,
+				'CONSTRAINT_TYPE'   => 'CHECK',
+				'CONSTRAINT_NAME'   => $name,
+			)
+		);
+
+		$this->delete_values(
+			$this->get_table_name( $table_is_temporary, 'check_constraints' ),
+			array(
+				'CONSTRAINT_SCHEMA' => $this->db_name,
+				'CONSTRAINT_NAME'   => $name,
+			)
+		);
+	}
+
 	/**
 	 * Analyze "columnDefinition" or "fieldDefinition" AST node and extract column data.
 	 *