/**
* Generates the EXISTS SQL string for the given SQL expression. The bulk of the logic for
* generating the sub-query is in this method.
*
* @param qualifier for which to generate the SQL
* @param expression to use during SQL generation
* @return SQL string for the current sub-query
*/
public String sqlStringForSQLExpression(EOQualifier qualifier, EOSQLExpression expression) {
if (null == qualifier || null == expression) {
return null;
}
ERXExistsQualifier existsQualifier = (ERXExistsQualifier) qualifier;
EOQualifier subqualifier = existsQualifier.subqualifier();
String baseKeyPath = existsQualifier.baseKeyPath();
EOEntity baseEntity = expression.entity();
EORelationship relationship = null;
// Walk the key path to the last entity.
if (baseKeyPath != null) {
for (Enumeration pathEnum =
NSArray.componentsSeparatedByString(baseKeyPath, ".").objectEnumerator();
pathEnum.hasMoreElements(); ) {
String path = (String) pathEnum.nextElement();
if (null == relationship) {
relationship = baseEntity.anyRelationshipNamed(path);
} else {
relationship = relationship.destinationEntity().anyRelationshipNamed(path);
}
}
}
EOEntity srcEntity = relationship != null ? relationship.entity() : baseEntity;
EOEntity destEntity = relationship != null ? relationship.destinationEntity() : baseEntity;
// We need to do a bunch of hand-waiving to get the right table aliases for the table used in
// the exists
// subquery and for the join clause back to the source table.
String sourceTableAlias =
"t0"; // The alias for the the source table of the baseKeyPath from the main query.
String destTableAlias; // The alias for the table used in the subquery.
if (!srcEntity.equals(baseEntity)) { // The exists clause is applied to the different table.
String sourceKeyPath = ERXStringUtilities.keyPathWithoutLastProperty(baseKeyPath);
sqlStringForAttributeNamedInExpression(sourceKeyPath, expression);
sqlStringForAttributeNamedInExpression(baseKeyPath, expression);
sourceTableAlias =
(String) expression.aliasesByRelationshipPath().valueForKey(sourceKeyPath);
destTableAlias = (String) expression.aliasesByRelationshipPath().valueForKey(baseKeyPath);
if (null == destTableAlias) {
destTableAlias =
"t" + (expression.aliasesByRelationshipPath().count()); // The first entry = "t0".
expression.aliasesByRelationshipPath().takeValueForKey(destTableAlias, baseKeyPath);
}
} else { // The exists clause is applied to the base table.
destTableAlias = "t" + expression.aliasesByRelationshipPath().count(); // Probably "t1"
}
EOAttribute sourceKeyAttribute = srcEntity.primaryKeyAttributes().lastObject();
String sourceKey = expression.sqlStringForAttribute(sourceKeyAttribute);
EOAttribute destKeyAttribute = relationship.destinationAttributes().lastObject();
String destKey = expression.sqlStringForAttribute(destKeyAttribute);
EOQualifier qual =
EOQualifierSQLGeneration.Support._schemaBasedQualifierWithRootEntity(
subqualifier, destEntity);
EOFetchSpecification fetchSpecification =
new EOFetchSpecification(destEntity.name(), qual, null, false, true, null);
EODatabaseContext context =
EODatabaseContext.registeredDatabaseContextForModel(
destEntity.model(), EOObjectStoreCoordinator.defaultCoordinator());
EOSQLExpressionFactory factory = context.database().adaptor().expressionFactory();
EOSQLExpression subExpression = factory.expressionForEntity(destEntity);
subExpression.aliasesByRelationshipPath().setObjectForKey(destTableAlias, "");
subExpression.setUseAliases(true);
subExpression.prepareSelectExpressionWithAttributes(
destEntity.primaryKeyAttributes(), false, fetchSpecification);
for (Enumeration bindEnumeration =
subExpression.bindVariableDictionaries().objectEnumerator();
bindEnumeration.hasMoreElements(); ) {
expression.addBindVariableDictionary((NSDictionary) bindEnumeration.nextElement());
}
StringBuffer sb = new StringBuffer();
sb.append(" EXISTS ( ");
sb.append(
ERXStringUtilities.replaceStringByStringInString(
"t0.", destTableAlias + ".", subExpression.statement()));
sb.append(" AND ");
sb.append(
ERXStringUtilities.replaceStringByStringInString("t0.", destTableAlias + ".", destKey));
sb.append(" = ");
sb.append(
ERXStringUtilities.replaceStringByStringInString(
"t0.", sourceTableAlias + ".", sourceKey));
sb.append(" ) ");
return sb.toString();
}
/**
* Generates the sql string for the given sql expression. Bulk of the logic for generating the
* sub-query is in this method.
*
* @param e a given sql expression
* @return sql string for the current sub-query.
*/
public String sqlStringForSQLExpression(EOSQLExpression e) {
StringBuffer sb = new StringBuffer();
if (attributeName != null) sb.append(e.sqlStringForAttributeNamed(attributeName));
else {
EOAttribute pk = (EOAttribute) e.entity().primaryKeyAttributes().lastObject();
sb.append(e.sqlStringForAttribute(pk));
}
sb.append(" IN ( ");
EOEntity entity =
entityName == null ? e.entity() : e.entity().model().modelGroup().entityNamed(entityName);
EOFetchSpecification fs =
new EOFetchSpecification(entity.name(), qualifier, null, false, true, null);
if (qualifier != null) {
qualifier =
EOQualifierSQLGeneration.Support._schemaBasedQualifierWithRootEntity(qualifier, entity);
}
if (qualifier != fs.qualifier()) {
fs.setQualifier(qualifier);
}
// ASSUME: This makes a few assumptions, if anyone can figure out a fool
// proof way that would be nice to get the model
// Note you can't use:
// EOAdaptor.adaptorWithModel(e.entity().model()).expressionFactory();
// as this creates a
//
EODatabaseContext context =
EODatabaseContext.registeredDatabaseContextForModel(
entity.model(), EOObjectStoreCoordinator.defaultCoordinator());
EOSQLExpressionFactory factory = context.database().adaptor().expressionFactory();
NSArray subAttributes =
destinationAttName != null
? new NSArray(entity.attributeNamed(destinationAttName))
: entity.primaryKeyAttributes();
EOSQLExpression subExpression = factory.expressionForEntity(entity);
// Arroz: Having this table identifier replacement causes serious
// problems if you have more than a table being processed in the subquery. Disabling
// it will apparently not cause problems, because t0 inside the subquery is not
// the same t0 outside it.
// subExpression.aliasesByRelationshipPath().setObjectForKey("t1", "");
subExpression.setUseAliases(true);
subExpression.prepareSelectExpressionWithAttributes(subAttributes, false, fs);
// EOSQLExpression
// expression=factory.selectStatementForAttributes(entity.primaryKeyAttributes(),
// false, fs, entity);
for (Enumeration bindEnumeration = subExpression.bindVariableDictionaries().objectEnumerator();
bindEnumeration.hasMoreElements(); ) {
e.addBindVariableDictionary((NSDictionary) bindEnumeration.nextElement());
}
// sb.append(ERXStringUtilities.replaceStringByStringInString("t0.",
// "t1.", subExpression.statement()));
sb.append(subExpression.statement());
sb.append(" ) ");
return sb.toString();
}
