Translate MySQL BINARY operator via SQLite COLLATE BINARY

'BINARY expr' is now emitted as 'expr COLLATE BINARY', which matches
MySQL's byte-by-byte comparison semantics and overrides declared column
collations like NOCASE.

Refs #31.

Author: JanJakes

packages/mysql-on-sqlite/src/sqlite/class-wp-pdo-mysql-on-sqlite.php

@@ -3924,9 +3924,9 @@ private function translate_token( WP_MySQL_Token $token ): ?string {
 				return 'AUTOINCREMENT';
 			case WP_MySQL_Lexer::BINARY_SYMBOL:
 				/*
-				 * There is no "BINARY expr" equivalent in SQLite. We look for the
-				 * keyword from a higher level to respect it in particular cases
-				 * (REGEXP, LIKE, etc.) and then remove it from the output here.
+				 * "BINARY expr" is translated in "translate_simple_expr_body()".
+				 * Returning null here is a safety net for any unhandled context
+				 * where a bare BINARY token would otherwise leak into the output.
 				 */
 				return null;
 			case WP_MySQL_Lexer::SQL_CALC_FOUND_ROWS_SYMBOL:
@@ -4274,6 +4274,19 @@ private function translate_simple_expr_body( WP_Parser_Node $node ): string {
 			);
 		}
 
+		/*
+		 * Translate "BINARY expr" to "expr COLLATE BINARY".
+		 *
+		 * The MySQL BINARY operator enforces byte-by-byte string comparison.
+		 * In SQLite, COLLATE BINARY is equivalent in comparison contexts.
+		 */
+		if ( null !== $token && WP_MySQL_Lexer::BINARY_SYMBOL === $token->id ) {
+			return sprintf(
+				'%s COLLATE BINARY',
+				$this->translate( $node->get_first_child_node( 'simpleExpr' ) )
+			);
+		}
+
 		/**
 		 * Translate MySQL CONVERT() expression.
 		 *

packages/mysql-on-sqlite/tests/WP_SQLite_Driver_Translation_Tests.php

@@ -136,6 +136,44 @@ public function testConvert(): void {
 		);
 	}
 
+	public function testBinary(): void {
+		// "BINARY expr" on the left side of comparison
+		$this->assertQuery(
+			'SELECT `a` COLLATE BINARY = `b` AS `BINARY a = b` FROM `t`',
+			'SELECT BINARY a = b FROM t'
+		);
+
+		// "BINARY expr" on the right side of comparison
+		$this->assertQuery(
+			'SELECT `a` = `b` COLLATE BINARY AS `a = BINARY b` FROM `t`',
+			'SELECT a = BINARY b FROM t'
+		);
+
+		// "BINARY literal"
+		$this->assertQuery(
+			"SELECT 'abc' COLLATE BINARY AS `BINARY 'abc'`",
+			"SELECT BINARY 'abc'"
+		);
+
+		// "BINARY expr" in ORDER BY
+		$this->assertQuery(
+			'SELECT `a` FROM `t` ORDER BY `a` COLLATE BINARY',
+			'SELECT a FROM t ORDER BY BINARY a'
+		);
+
+		// "BINARY expr" in GROUP BY
+		$this->assertQuery(
+			'SELECT `a` FROM `t` GROUP BY `a` COLLATE BINARY',
+			'SELECT a FROM t GROUP BY BINARY a'
+		);
+
+		// "BINARY expr" wrapping a parenthesized expression
+		$this->assertQuery(
+			"SELECT ( `a` || `b` ) COLLATE BINARY = 'x' AS `BINARY (a || b) = 'x'` FROM `t`",
+			"SELECT BINARY (a || b) = 'x' FROM t"
+		);
+	}
+
 	public function testInsert(): void {
 		$this->driver->query( 'CREATE TABLE t (c INT, c1 INT, c2 INT)' );
 		$this->driver->query( 'CREATE TABLE t1 (c1 INT, c2 INT)' );