[Hibernate-commits] Hibernate Code SVN: r10174 - in trunk/Hibernate3/src/org/hibernate/dialect: . function

[<hib...@li...>]

Author: ste...@jb...
Date: 2006-07-26 16:11:52 -0400 (Wed, 26 Jul 2006)
New Revision: 10174

Added:
   trunk/Hibernate3/src/org/hibernate/dialect/function/AnsiTrimEmulationFunction.java
Modified:
   trunk/Hibernate3/src/org/hibernate/dialect/DerbyDialect.java
Log:
test ansi trim emulation on derby

Modified: trunk/Hibernate3/src/org/hibernate/dialect/DerbyDialect.java
===================================================================
--- trunk/Hibernate3/src/org/hibernate/dialect/DerbyDialect.java	2006-07-26 18:04:07 UTC (rev 10173)
+++ trunk/Hibernate3/src/org/hibernate/dialect/DerbyDialect.java	2006-07-26 20:11:52 UTC (rev 10174)
@@ -3,6 +3,7 @@
 
 import org.hibernate.Hibernate;
 import org.hibernate.dialect.function.VarArgsSQLFunction;
+import org.hibernate.dialect.function.AnsiTrimEmulationFunction;
 import org.hibernate.id.TableHiLoGenerator;
 import org.hibernate.sql.CaseFragment;
 import org.hibernate.sql.DerbyCaseFragment;
@@ -20,6 +21,7 @@
 	public DerbyDialect() {
 		super();
 		registerFunction( "concat", new VarArgsSQLFunction( Hibernate.STRING, "(","||",")" ) );
+		registerFunction( "trim", new AnsiTrimEmulationFunction() );
 	}
 
 	/**

Added: trunk/Hibernate3/src/org/hibernate/dialect/function/AnsiTrimEmulationFunction.java
===================================================================
--- trunk/Hibernate3/src/org/hibernate/dialect/function/AnsiTrimEmulationFunction.java	2006-07-26 18:04:07 UTC (rev 10173)
+++ trunk/Hibernate3/src/org/hibernate/dialect/function/AnsiTrimEmulationFunction.java	2006-07-26 20:11:52 UTC (rev 10174)
@@ -0,0 +1,146 @@
+package org.hibernate.dialect.function;
+
+import org.hibernate.Hibernate;
+import org.hibernate.QueryException;
+import org.hibernate.engine.Mapping;
+import org.hibernate.engine.SessionFactoryImplementor;
+import org.hibernate.type.Type;
+
+import java.util.List;
+import java.util.ArrayList;
+
+/**
+ * A {@link SQLFunction} implementation that emulates the ANSI SQL trim function
+ * on dialects which do not support the full definition.  However, this function
+ * definition does assume the availability of ltrim, rtrim, and replace functions
+ * which it uses in various combinations to emulate the desired ANSI trim()
+ * functionality.
+ *
+ * @author Steve Ebersole
+ */
+public class AnsiTrimEmulationFunction implements SQLFunction {
+
+	private static final SQLFunction LEADING_SPACE_TRIM = new SQLFunctionTemplate( Hibernate.STRING, "ltrim( ?1 )");
+	private static final SQLFunction TRAILING_SPACE_TRIM = new SQLFunctionTemplate( Hibernate.STRING, "rtrim( ?1 )");
+	private static final SQLFunction BOTH_SPACE_TRIM = new SQLFunctionTemplate( Hibernate.STRING, "ltrim( rtrim( ?1 ) )");
+	private static final SQLFunction BOTH_SPACE_TRIM_FROM = new SQLFunctionTemplate( Hibernate.STRING, "ltrim( rtrim( ?2 ) )");
+
+	private static final SQLFunction LEADING_TRIM = new SQLFunctionTemplate( Hibernate.STRING, "replace( replace( rtrim( replace( replace( ?1, ' ', '${space}$' ), ?2, ' ' ) ), ' ', ?2 ), '${space}$', ' ' )" );
+	private static final SQLFunction TRAILING_TRIM = new SQLFunctionTemplate( Hibernate.STRING, "replace( replace( ltrim( replace( replace( ?1, ' ', '${space}$' ), ?2, ' ' ) ), ' ', ?2 ), '${space}$', ' ' )" );
+	private static final SQLFunction BOTH_TRIM = new SQLFunctionTemplate( Hibernate.STRING, "replace( replace( ltrim( rtrim( replace( replace( ?1, ' ', '${space}$' ), ?2, ' ' ) ) ), ' ', ?2 ), '${space}$', ' ' )" );
+
+	public Type getReturnType(Type columnType, Mapping mapping) throws QueryException {
+		return Hibernate.STRING;
+	}
+
+	public boolean hasArguments() {
+		return true;
+	}
+
+	public boolean hasParenthesesIfNoArguments() {
+		return false;
+	}
+
+	public String render(List args, SessionFactoryImplementor factory) throws QueryException {
+		// according to both the ANSI-SQL and EJB3 specs, trim can either take
+		// exactly one parameter or a variable number of parameters between 1 and 4.
+		// from the SQL spec:
+		//
+		// <trim function> ::=
+		//      TRIM <left paren> <trim operands> <right paren>
+		//
+		// <trim operands> ::=
+		//      [ [ <trim specification> ] [ <trim character> ] FROM ] <trim source>
+		//
+		// <trim specification> ::=
+		//      LEADING
+		//      | TRAILING
+		//      | BOTH
+		//
+		// If only <trim specification> is omitted, BOTH is assumed;
+		// if <trim character> is omitted, space is assumed
+		if ( args.size() == 1 ) {
+			// we have the form: trim(trimSource)
+			//      so we trim leading and trailing spaces
+			return BOTH_SPACE_TRIM.render( args, factory );
+		}
+		else if ( "from".equalsIgnoreCase( ( String ) args.get( 0 ) ) ) {
+			// we have the form: trim(from trimSource).
+			//      This is functionally equivalent to trim(trimSource)
+			return BOTH_SPACE_TRIM_FROM.render( args, factory );
+		}
+		else {
+			// otherwise, a trim-specification and/or a trim-character
+			// have been specified;  we need to decide which options
+			// are present and "do the right thing"
+			boolean leading = true;         // should leading trim-characters be trimmed?
+			boolean trailing = true;        // should trailing trim-characters be trimmed?
+			String trimCharacter = null;    // the trim-character
+			String trimSource = null;       // the trim-source
+
+			// potentialTrimCharacterArgIndex = 1 assumes that a
+			// trim-specification has been specified.  we handle the
+			// exception to that explicitly
+			int potentialTrimCharacterArgIndex = 1;
+			String firstArg = ( String ) args.get( 0 );
+			if ( "leading".equalsIgnoreCase( firstArg ) ) {
+				trailing = false;
+			}
+			else if ( "trailing".equalsIgnoreCase( firstArg ) ) {
+				leading = false;
+			}
+			else if ( "both".equalsIgnoreCase( firstArg ) ) {
+			}
+			else {
+				potentialTrimCharacterArgIndex = 0;
+			}
+
+			String potentialTrimCharacter = ( String ) args.get( potentialTrimCharacterArgIndex );
+			if ( "from".equalsIgnoreCase( potentialTrimCharacter ) ) {
+				trimCharacter = "' '";
+				trimSource = ( String ) args.get( potentialTrimCharacterArgIndex + 1 );
+			}
+			else if ( potentialTrimCharacterArgIndex + 1 >= args.size() ) {
+				trimCharacter = "' '";
+				trimSource = potentialTrimCharacter;
+			}
+			else {
+				trimCharacter = potentialTrimCharacter;
+				if ( "from".equalsIgnoreCase( ( String ) args.get( potentialTrimCharacterArgIndex + 1 ) ) ) {
+					trimSource = ( String ) args.get( potentialTrimCharacterArgIndex + 2 );
+				}
+				else {
+					trimSource = ( String ) args.get( potentialTrimCharacterArgIndex + 1 );
+				}
+			}
+
+			List argsToUse = null;
+			argsToUse = new ArrayList();
+			argsToUse.add( trimSource );
+			argsToUse.add( trimCharacter );
+
+			if ( trimCharacter.equals( "' '" ) ) {
+				if ( leading && trailing ) {
+					return BOTH_SPACE_TRIM.render( argsToUse, factory );
+				}
+				else if ( leading ) {
+					return LEADING_SPACE_TRIM.render( argsToUse, factory );
+				}
+				else {
+					return TRAILING_SPACE_TRIM.render( argsToUse, factory );
+				}
+			}
+			else {
+				if ( leading && trailing ) {
+					return BOTH_TRIM.render( argsToUse, factory );
+				}
+				else if ( leading ) {
+					return LEADING_TRIM.render( argsToUse, factory );
+				}
+				else {
+					return TRAILING_TRIM.render( argsToUse, factory );
+				}
+			}
+		}
+	}
+}