Add support for DEFAULT (expression) in column definitions

tests/WP_SQLite_Driver_Tests.php

@@ -11238,4 +11238,81 @@ public function testVersionFunction(): void {
 		$result = $this->engine->query( 'SELECT VERSION()' );
 		$this->assertSame( '8.0.38', $result[0]->{'VERSION()'} );
 	}
+
+	/**
+	 * Test CREATE TABLE with DEFAULT (now()) - GitHub issue #300
+	 * Tests that DEFAULT with function calls in parentheses works correctly in AST driver.
+	 *
+	 * @see https://github.com/WordPress/sqlite-database-integration/issues/300
+	 */
+	public function testCreateTableWithDefaultNowFunction(): void {
+		// Test the exact SQL from the issue
+		$this->assertQuery(
+			'CREATE TABLE `test_now_default` (
+				`id` int NOT NULL,
+				`updated` timestamp NOT NULL DEFAULT (now()) ON UPDATE CURRENT_TIMESTAMP
+			) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;'
+		);
+
+		// Insert a row to verify the default value works
+		$this->assertQuery( 'INSERT INTO test_now_default (id) VALUES (1)' );
+		$result = $this->assertQuery( 'SELECT * FROM test_now_default WHERE id = 1' );
+		$this->assertCount( 1, $result );
+
+		// Verify the updated timestamp was set (should match YYYY-MM-DD HH:MM:SS format)
+		$this->assertRegExp( '/\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d/', $result[0]->updated );
+
+		// SHOW CREATE TABLE
+		$this->assertQuery( 'SHOW CREATE TABLE test_now_default' );
+		$results = $this->engine->get_query_results();
+		$this->assertEquals(
+			implode(
+				"\n",
+				array(
+					'CREATE TABLE `test_now_default` (',
+					'  `id` int NOT NULL,',
+					'  `updated` timestamp NOT NULL DEFAULT ( now( ) ) ON UPDATE CURRENT_TIMESTAMP',
+					') ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci',
+				)
+			),
+			$results[0]->{'Create Table'}
+		);
+	}
+
+	public function testCreateTableWithDefaultExpressions(): void {
+		$this->assertQuery(
+			'CREATE TABLE t (
+				id int NOT NULL,
+				col1 int NOT NULL DEFAULT (1 + 2),
+				col2 datetime NOT NULL DEFAULT (DATE_ADD(NOW(), INTERVAL 1 YEAR)),
+				col3 varchar(255) NOT NULL DEFAULT (CONCAT(\'a\', \'b\'))
+			)'
+		);
+
+		// Insert a row and verify the default values
+		$this->assertQuery( 'INSERT INTO t (id) VALUES (1)' );
+		$this->assertQuery( 'SELECT * FROM t WHERE id = 1' );
+		$results = $this->engine->get_query_results();
+		$this->assertEquals( 3, $results[0]->col1 );
+		$this->assertStringStartsWith( ( gmdate( 'Y' ) + 1 ) . '-', $results[0]->col2 );
+		$this->assertEquals( 'ab', $results[0]->col3 );
+
+		// SHOW CREATE TABLE
+		$this->assertQuery( 'SHOW CREATE TABLE t' );
+		$results = $this->engine->get_query_results();
+		$this->assertEquals(
+			implode(
+				"\n",
+				array(
+					'CREATE TABLE `t` (',
+					'  `id` int NOT NULL,',
+					'  `col1` int NOT NULL DEFAULT ( 1 + 2 ),',
+					'  `col2` datetime NOT NULL DEFAULT ( DATE_ADD( NOW( ) , INTERVAL 1 YEAR ) ),',
+					"  `col3` varchar(255) NOT NULL DEFAULT ( CONCAT( 'a' , 'b' ) )",
+					') ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci',
+				)
+			),
+			$results[0]->{'Create Table'}
+		);
+	}
 }

tests/WP_SQLite_Translator_Tests.php

@@ -3510,4 +3510,41 @@ public static function mysqlVariablesToTest() {
 			array( '@@sEssIOn.sqL_moDe' ),
 		);
 	}
+
+	/**
+	 * Test CREATE TABLE with DEFAULT (now()) - GitHub issue #300
+	 * Tests that DEFAULT with function calls in parentheses works correctly.
+	 */
+	public function testCreateTableWithDefaultNowFunction() {
+		// Test the exact SQL from the issue
+		$this->assertQuery(
+			'CREATE TABLE `test_now_default` (
+				`id` int NOT NULL,
+				`updated` timestamp NOT NULL DEFAULT (now()) ON UPDATE CURRENT_TIMESTAMP
+			) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;'
+		);
+
+		// Verify the table was created successfully
+		$results = $this->assertQuery( 'DESCRIBE test_now_default;' );
+		$this->assertCount( 2, $results );
+
+		// Verify the updated column has the correct properties
+		$updated_field = $results[1];
+		$this->assertEquals( 'updated', $updated_field->Field );
+		$this->assertEquals( 'timestamp', $updated_field->Type );
+		$this->assertEquals( 'NO', $updated_field->Null );
+
+		// Insert a row to verify the default value works
+		$this->assertQuery( 'INSERT INTO test_now_default (id) VALUES (1)' );
+		$result = $this->assertQuery( 'SELECT * FROM test_now_default WHERE id = 1' );
+		$this->assertCount( 1, $result );
+
+		// Verify the updated timestamp was set (should match YYYY-MM-DD HH:MM:SS format)
+		$this->assertRegExp( '/\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d/', $result[0]->updated );
+
+		// Test ON UPDATE trigger works
+		$this->assertQuery( 'UPDATE test_now_default SET id = 2 WHERE id = 1' );
+		$result = $this->assertQuery( 'SELECT * FROM test_now_default WHERE id = 2' );
+		$this->assertRegExp( '/\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d/', $result[0]->updated );
+	}
 }

wp-includes/sqlite-ast/class-wp-sqlite-driver.php

@@ -5413,15 +5413,20 @@ private function get_sqlite_create_table_statement(
 				$query            .= ' PRIMARY KEY AUTOINCREMENT';
 			}
 			if ( null !== $column['COLUMN_DEFAULT'] ) {
-				// @TODO: Handle defaults with expression values (DEFAULT_GENERATED).
-
 				// Handle DEFAULT CURRENT_TIMESTAMP. This works only with timestamp
 				// and datetime columns. For other column types, it's just a string.
 				if (
 					'CURRENT_TIMESTAMP' === $column['COLUMN_DEFAULT']
 					&& ( 'timestamp' === $column['DATA_TYPE'] || 'datetime' === $column['DATA_TYPE'] )
 				) {
 					$query .= ' DEFAULT CURRENT_TIMESTAMP';
+				} elseif ( str_contains( $column['EXTRA'], 'DEFAULT_GENERATED' ) ) {
+					// Handle DEFAULT values with expressions (DEFAULT_GENERATED).
+					// Translate the default clause from MySQL to SQLite.
+					$ast            = $this->create_parser( 'SELECT ' . $column['COLUMN_DEFAULT'] )->parse();
+					$expr           = $ast->get_first_descendant_node( 'selectItem' )->get_first_child_node();
+					$default_clause = $this->translate( $expr );
+					$query         .= ' DEFAULT ' . $default_clause;
 				} else {
 					$query .= ' DEFAULT ' . $this->connection->quote( $column['COLUMN_DEFAULT'] );
 				}
@@ -5713,7 +5718,11 @@ private function get_mysql_create_table_statement( bool $table_is_temporary, str
 			) {
 				$sql .= ' DEFAULT CURRENT_TIMESTAMP';
 			} elseif ( null !== $column['COLUMN_DEFAULT'] ) {
-				$sql .= ' DEFAULT ' . $this->quote_mysql_utf8_string_literal( $column['COLUMN_DEFAULT'] );
+				if ( str_contains( $column['EXTRA'], 'DEFAULT_GENERATED' ) ) {
+					$sql .= ' DEFAULT ' . $column['COLUMN_DEFAULT'];
+				} else {
+					$sql .= ' DEFAULT ' . $this->quote_mysql_utf8_string_literal( $column['COLUMN_DEFAULT'] );
+				}
 			} elseif ( 'YES' === $column['IS_NULLABLE'] ) {
 				$sql .= ' DEFAULT NULL';
 			}

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

@@ -2088,7 +2088,25 @@ private function get_column_default( WP_Parser_Node $node ): ?string {
 			return $this->get_value( $signed_literal );
 		}
 
-		throw new Exception( 'DEFAULT values with expressions are not yet supported.' );
+		// DEFAULT (expression) - MySQL 8.0.13+ supports exprWithParentheses
+		$expr_with_parens = $default_attr->get_first_child_node( 'exprWithParentheses' );
+		if ( $expr_with_parens ) {
+			$default_clause = '';
+			foreach ( $expr_with_parens->get_descendant_tokens() as $i => $token ) {
+				if ( WP_MySQL_Lexer::OPEN_PAR_SYMBOL === $token->id ) {
+					// TODO: This is just a quick fix to avoid inserting whitespace
+					//       before '(', which would break function call expressions.
+					//       The proper fix is to implement a "$node->get_bytes()" API.
+					//       This same applies to the CHECK (expression) case as well.
+					$default_clause .= $token->get_bytes();
+				} else {
+					$default_clause .= ( $i > 0 ? ' ' : '' ) . $token->get_bytes();
+				}
+			}
+			return $default_clause;
+		}
+
+		throw new Exception( 'DEFAULT value of this type is not supported.' );
 	}
 
 	/**

wp-includes/sqlite/class-wp-sqlite-translator.php

@@ -1149,7 +1149,28 @@ private function parse_mysql_create_table_field() {
 				WP_SQLite_Token::FLAG_KEYWORD_FUNCTION,
 				array( 'DEFAULT' )
 			) ) {
-				$result->default = $this->rewriter->consume()->token;
+				// Consume the next token (could be a value, opening paren, etc.)
+				$default_token   = $this->rewriter->consume();
+				$result->default = $default_token->token;
+
+				// Check if the default value is wrapped in parentheses (for function calls like (now()))
+				if ( $default_token->matches( WP_SQLite_Token::TYPE_OPERATOR, null, array( '(' ) ) ) {
+					// Track parenthesis depth to consume the complete expression
+					$paren_depth   = 1;
+					$default_value = '(';
+
+					while ( $paren_depth > 0 && ( $next_token = $this->rewriter->consume() ) ) {
+						$default_value .= $next_token->token;
+
+						if ( $next_token->matches( WP_SQLite_Token::TYPE_OPERATOR, null, array( '(' ) ) ) {
+							++$paren_depth;
+						} elseif ( $next_token->matches( WP_SQLite_Token::TYPE_OPERATOR, null, array( ')' ) ) ) {
+							--$paren_depth;
+						}
+					}
+
+					$result->default = $default_value;
+				}
 				continue;
 			}