HHH-15736 Handle backslash escapes in like patterns

hibernate · Dec 12, 2022 · 254724d · 254724d
1 parent a5525a9
commit 254724d
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Showing 13 changed files with 539 additions and 11 deletions.
diff --git a/...nity-dialects/src/main/java/org/hibernate/community/dialect/H2LegacySqlAstTranslator.java b/...nity-dialects/src/main/java/org/hibernate/community/dialect/H2LegacySqlAstTranslator.java
@@ -31,6 +31,7 @@
 import org.hibernate.sql.ast.tree.from.TableReference;
 import org.hibernate.sql.ast.tree.predicate.BooleanExpressionPredicate;
 import org.hibernate.sql.ast.tree.predicate.InSubQueryPredicate;
+import org.hibernate.sql.ast.tree.predicate.LikePredicate;
 import org.hibernate.sql.ast.tree.select.QueryPart;
 import org.hibernate.sql.ast.tree.select.SelectClause;
 import org.hibernate.sql.exec.spi.JdbcOperation;
@@ -209,7 +210,17 @@ protected boolean renderPrimaryTableReference(TableGroup tableGroup, LockMode lo
 			}
 		}
 		return super.renderPrimaryTableReference( tableGroup, lockMode );
+	}
 
+	@Override
+	public void visitLikePredicate(LikePredicate likePredicate) {
+		super.visitLikePredicate( likePredicate );
+		// Custom implementation because H2 uses backslash as the default escape character
+		// We can override this by specifying an empty escape character
+		// See http://www.h2database.com/html/grammar.html#like_predicate_right_hand_side
+		if ( likePredicate.getEscapeCharacter() == null ) {
+			appendSql( " escape ''" );
+		}
 	}
 
 	@Override

diff --git a/...ommunity-dialects/src/main/java/org/hibernate/community/dialect/MariaDBLegacyDialect.java b/...ommunity-dialects/src/main/java/org/hibernate/community/dialect/MariaDBLegacyDialect.java
@@ -25,6 +25,7 @@
 import org.hibernate.query.spi.QueryEngine;
 import org.hibernate.sql.ast.SqlAstTranslator;
 import org.hibernate.sql.ast.SqlAstTranslatorFactory;
+import org.hibernate.sql.ast.spi.SqlAppender;
 import org.hibernate.sql.ast.spi.StandardSqlAstTranslatorFactory;
 import org.hibernate.sql.ast.tree.Statement;
 import org.hibernate.sql.exec.spi.JdbcOperation;
@@ -51,7 +52,11 @@ public MariaDBLegacyDialect(DatabaseVersion version) {
 	}
 
 	public MariaDBLegacyDialect(DialectResolutionInfo info) {
-		super( createVersion( info ), getCharacterSetBytesPerCharacter( info.getDatabaseMetadata() ) );
+		super(
+				createVersion( info ),
+				getCharacterSetBytesPerCharacter( info.getDatabaseMetadata() ),
+				getNoBackslashEscapes( info.getDatabaseMetadata() )
+		);
 		registerKeywords( info );
 	}
 
@@ -193,4 +198,26 @@ public IdentifierHelper buildIdentifierHelper(IdentifierHelperBuilder builder, D
 
 		return super.buildIdentifierHelper( builder, dbMetaData );
 	}
+
+	protected void appendLikeLiteral(SqlAppender appender, String literal) {
+		appender.appendSql( '\'' );
+		for ( int i = 0; i < literal.length(); i++ ) {
+			final char c = literal.charAt( i );
+			switch ( c ) {
+				case '\'':
+					appender.appendSql( '\'' );
+					break;
+				case '\\':
+					if ( !isNoBackslashEscapesEnabled() ) {
+						appender.appendSql( "\\\\\\" );
+					}
+					else {
+						appender.appendSql( '\\' );
+					}
+					break;
+			}
+			appender.appendSql( c );
+		}
+		appender.appendSql( '\'' );
+	}
 }
diff --git a/...dialects/src/main/java/org/hibernate/community/dialect/MariaDBLegacySqlAstTranslator.java b/...dialects/src/main/java/org/hibernate/community/dialect/MariaDBLegacySqlAstTranslator.java
@@ -6,6 +6,8 @@
  */
 package org.hibernate.community.dialect;
 
+import org.hibernate.dialect.Dialect;
+import org.hibernate.dialect.MariaDBDialect;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.query.sqm.ComparisonOperator;
 import org.hibernate.sql.ast.spi.AbstractSqlAstTranslator;
@@ -16,6 +18,7 @@
 import org.hibernate.sql.ast.tree.expression.Summarization;
 import org.hibernate.sql.ast.tree.from.QueryPartTableReference;
 import org.hibernate.sql.ast.tree.predicate.BooleanExpressionPredicate;
+import org.hibernate.sql.ast.tree.predicate.LikePredicate;
 import org.hibernate.sql.ast.tree.select.QueryGroup;
 import org.hibernate.sql.ast.tree.select.QueryPart;
 import org.hibernate.sql.ast.tree.select.QuerySpec;
@@ -157,6 +160,75 @@ else if ( expression instanceof Summarization ) {
 		}
 	}
 
+	@Override
+	public void visitLikePredicate(LikePredicate likePredicate) {
+		if ( likePredicate.isCaseSensitive() ) {
+			likePredicate.getMatchExpression().accept( this );
+			if ( likePredicate.isNegated() ) {
+				appendSql( " not" );
+			}
+			appendSql( " like " );
+			escapeLikePattern( likePredicate.getPattern(), likePredicate.getEscapeCharacter() );
+		}
+		else {
+			appendSql( getDialect().getLowercaseFunction() );
+			appendSql( OPEN_PARENTHESIS );
+			likePredicate.getMatchExpression().accept( this );
+			appendSql( CLOSE_PARENTHESIS );
+			if ( likePredicate.isNegated() ) {
+				appendSql( " not" );
+			}
+			appendSql( " like " );
+			appendSql( getDialect().getLowercaseFunction() );
+			appendSql( OPEN_PARENTHESIS );
+			escapeLikePattern( likePredicate.getPattern(), likePredicate.getEscapeCharacter() );
+			appendSql( CLOSE_PARENTHESIS );
+		}
+		if ( likePredicate.getEscapeCharacter() != null ) {
+			appendSql( " escape " );
+			likePredicate.getEscapeCharacter().accept( this );
+		}
+	}
+
+	protected void escapeLikePattern(Expression pattern, Expression escapeCharacter) {
+		// Check if escapeCharacter was explicitly set and do nothing in that case
+		// Note: this does not cover cases where it's set via parameter binding
+		boolean isExplicitEscape = false;
+		if ( escapeCharacter instanceof Literal ) {
+			Object literalValue = ( (Literal) escapeCharacter ).getLiteralValue();
+			isExplicitEscape = literalValue != null && !literalValue.toString().equals( "" );
+		}
+		if ( isExplicitEscape ) {
+			pattern.accept( this );
+		}
+		else {
+			// Since escape with empty or null character is ignored we need
+			// four backslashes to render a single one in a like pattern
+			// See https://mariadb.com/kb/en/like/#description
+			if ( pattern instanceof Literal ) {
+				Object literalValue = ( (Literal) pattern ).getLiteralValue();
+				if ( literalValue == null ) {
+					pattern.accept( this );
+				}
+				else {
+					getDialect().appendLikeLiteral( this, literalValue.toString() );
+				}
+			}
+			else {
+				// replace(<value>, '\\', '\\\\')
+				appendSql( "replace" );
+				appendSql( OPEN_PARENTHESIS );
+				pattern.accept( this );
+				String replaceParams = "'\\\\','\\\\\\\\'";
+				if ( getDialect().isNoBackslashEscapesEnabled() ) {
+					replaceParams = replaceParams.replace( "\\\\", "\\" );
+				}
+				appendSql( "," + replaceParams );
+				appendSql( CLOSE_PARENTHESIS );
+			}
+		}
+	}
+
 	@Override
 	public boolean supportsRowValueConstructorSyntaxInSet() {
 		return false;
@@ -178,6 +250,11 @@ protected boolean supportsDistinctFromPredicate() {
 		return true;
 	}
 
+	@Override
+	public MariaDBLegacyDialect getDialect() {
+		return (MariaDBLegacyDialect) super.getDialect();
+	}
+
 	private boolean supportsWindowFunctions() {
 		return getDialect().getVersion().isSameOrAfter( 10, 2 );
 	}

diff --git a/...-community-dialects/src/main/java/org/hibernate/community/dialect/MySQLLegacyDialect.java b/...-community-dialects/src/main/java/org/hibernate/community/dialect/MySQLLegacyDialect.java
@@ -11,6 +11,7 @@
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Types;
+import java.util.Arrays;
 
 import org.hibernate.LockOptions;
 import org.hibernate.PessimisticLockException;
@@ -141,22 +142,29 @@ public Size resolveSize(
 	private final int maxVarcharLength;
 	private final int maxVarbinaryLength;
 
+	private final boolean noBackslashEscapesEnabled;
+
 	public MySQLLegacyDialect() {
 		this( DatabaseVersion.make( 5, 0 ) );
 	}
 
 	public MySQLLegacyDialect(DatabaseVersion version) {
-		this( version, 4 );
+		this( version, 4, false );
 	}
 
-	public MySQLLegacyDialect(DatabaseVersion version, int bytesPerCharacter) {
+	public MySQLLegacyDialect(DatabaseVersion version, int bytesPerCharacter, boolean noBackslashEscapes) {
 		super( version );
 		maxVarcharLength = maxVarcharLength( getMySQLVersion(), bytesPerCharacter ); //conservative assumption
 		maxVarbinaryLength = maxVarbinaryLength( getMySQLVersion() );
+		noBackslashEscapesEnabled = noBackslashEscapes;
 	}
 
 	public MySQLLegacyDialect(DialectResolutionInfo info) {
-		this( createVersion( info ), getCharacterSetBytesPerCharacter( info.getDatabaseMetadata() ) );
+		this(
+				createVersion( info ),
+				getCharacterSetBytesPerCharacter( info.getDatabaseMetadata() ),
+				getNoBackslashEscapes( info.getDatabaseMetadata() )
+		);
 		registerKeywords( info );
 	}
 
@@ -396,6 +404,22 @@ protected static int getCharacterSetBytesPerCharacter(DatabaseMetaData databaseM
 		return 4;
 	}
 
+	protected static boolean getNoBackslashEscapes(DatabaseMetaData databaseMetaData) {
+		// See https://dev.mysql.com/doc/refman/8.0/en/sql-mode.html
+		try (java.sql.Statement s = databaseMetaData.getConnection().createStatement() ) {
+			final ResultSet rs = s.executeQuery( "SELECT @@sql_mode" );
+			if ( rs.next() ) {
+				final String sqlMode = rs.getString( 1 );
+				final String expectedValue = "no_backslash_escapes";
+				return sqlMode.toLowerCase().contains( expectedValue );
+			}
+		}
+		catch (SQLException ex) {
+			// Ignore
+		}
+		return false;
+	}
+
 	private static int maxVarbinaryLength(DatabaseVersion version) {
 		return version.isBefore( 5 ) ? 255 : 65_535;
 	}
@@ -430,6 +454,10 @@ public int getMaxVarbinaryLength() {
 		return maxVarbinaryLength;
 	}
 
+	public boolean isNoBackslashEscapesEnabled() {
+		return noBackslashEscapesEnabled;
+	}
+
 	@Override
 	public String getNullColumnString(String columnType) {
 		// Good job MySQL https://dev.mysql.com/doc/refman/8.0/en/timestamp-initialization.html

diff --git a/...y-dialects/src/main/java/org/hibernate/community/dialect/MySQLLegacySqlAstTranslator.java b/...y-dialects/src/main/java/org/hibernate/community/dialect/MySQLLegacySqlAstTranslator.java
@@ -6,6 +6,7 @@
  */
 package org.hibernate.community.dialect;
 
+import org.hibernate.dialect.MySQLDialect;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.query.sqm.ComparisonOperator;
 import org.hibernate.sql.ast.spi.AbstractSqlAstTranslator;
@@ -16,6 +17,7 @@
 import org.hibernate.sql.ast.tree.from.QueryPartTableReference;
 import org.hibernate.sql.ast.tree.from.ValuesTableReference;
 import org.hibernate.sql.ast.tree.predicate.BooleanExpressionPredicate;
+import org.hibernate.sql.ast.tree.predicate.LikePredicate;
 import org.hibernate.sql.ast.tree.select.QueryGroup;
 import org.hibernate.sql.ast.tree.select.QueryPart;
 import org.hibernate.sql.ast.tree.select.QuerySpec;
@@ -139,6 +141,17 @@ else if ( expression instanceof Summarization ) {
 		}
 	}
 
+	@Override
+	public void visitLikePredicate(LikePredicate likePredicate) {
+		super.visitLikePredicate( likePredicate );
+		// Custom implementation because H2 uses backslash as the default escape character
+		// We can override this by specifying an empty escape character
+		// See http://www.h2database.com/html/grammar.html#like_predicate_right_hand_side
+		if ( !( (MySQLLegacyDialect) getDialect() ).isNoBackslashEscapesEnabled() && likePredicate.getEscapeCharacter() == null ) {
+			appendSql( " escape ''" );
+		}
+	}
+
 	@Override
 	public boolean supportsRowValueConstructorSyntaxInSet() {
 		return false;

diff --git a/hibernate-core/src/main/java/org/hibernate/dialect/H2SqlAstTranslator.java b/hibernate-core/src/main/java/org/hibernate/dialect/H2SqlAstTranslator.java
@@ -32,6 +32,7 @@
 import org.hibernate.sql.ast.tree.from.TableReference;
 import org.hibernate.sql.ast.tree.predicate.BooleanExpressionPredicate;
 import org.hibernate.sql.ast.tree.predicate.InSubQueryPredicate;
+import org.hibernate.sql.ast.tree.predicate.LikePredicate;
 import org.hibernate.sql.ast.tree.select.QueryPart;
 import org.hibernate.sql.ast.tree.select.SelectClause;
 import org.hibernate.sql.exec.spi.JdbcOperation;
@@ -244,7 +245,17 @@ protected boolean renderPrimaryTableReference(TableGroup tableGroup, LockMode lo
 			}
 		}
 		return super.renderPrimaryTableReference( tableGroup, lockMode );
+	}
 
+	@Override
+	public void visitLikePredicate(LikePredicate likePredicate) {
+		super.visitLikePredicate( likePredicate );
+		// Custom implementation because H2 uses backslash as the default escape character
+		// We can override this by specifying an empty escape character
+		// See http://www.h2database.com/html/grammar.html#like_predicate_right_hand_side
+		if ( likePredicate.getEscapeCharacter() == null ) {
+			appendSql( " escape ''" );
+		}
 	}
 
 	@Override

diff --git a/hibernate-core/src/main/java/org/hibernate/dialect/MariaDBDialect.java b/hibernate-core/src/main/java/org/hibernate/dialect/MariaDBDialect.java
@@ -22,6 +22,7 @@
 import org.hibernate.service.ServiceRegistry;
 import org.hibernate.sql.ast.SqlAstTranslator;
 import org.hibernate.sql.ast.SqlAstTranslatorFactory;
+import org.hibernate.sql.ast.spi.SqlAppender;
 import org.hibernate.sql.ast.spi.StandardSqlAstTranslatorFactory;
 import org.hibernate.sql.ast.tree.Statement;
 import org.hibernate.sql.exec.spi.JdbcOperation;
@@ -56,7 +57,11 @@ public MariaDBDialect(DatabaseVersion version) {
 	}
 
 	public MariaDBDialect(DialectResolutionInfo info) {
-		super( createVersion( info ), getCharacterSetBytesPerCharacter( info.getDatabaseMetadata() ) );
+		super(
+				createVersion( info ),
+				getCharacterSetBytesPerCharacter( info.getDatabaseMetadata() ),
+				getNoBackslashEscapes( info.getDatabaseMetadata() )
+		);
 		registerKeywords( info );
 	}
 
@@ -238,4 +243,26 @@ public IdentifierHelper buildIdentifierHelper(IdentifierHelperBuilder builder, D
 
 		return super.buildIdentifierHelper( builder, dbMetaData );
 	}
+
+	protected void appendLikeLiteral(SqlAppender appender, String literal) {
+		appender.appendSql( '\'' );
+		for ( int i = 0; i < literal.length(); i++ ) {
+			final char c = literal.charAt( i );
+			switch ( c ) {
+				case '\'':
+					appender.appendSql( '\'' );
+					break;
+				case '\\':
+					if ( !isNoBackslashEscapesEnabled() ) {
+						appender.appendSql( "\\\\\\" );
+					}
+					else {
+						appender.appendSql( '\\' );
+					}
+					break;
+			}
+			appender.appendSql( c );
+		}
+		appender.appendSql( '\'' );
+	}
 }