@Override
public void appendTo(HqlQuery query, HqlQueryBuilderParams params) {
HqlQueryValueImpl from = new HqlQueryValueImpl();
from.appendHql(helper.getEntityName(root.getPropertyType()));
from.appendHql(" ").append(root.getAlias());
for (TypeSafeQueryJoin<?> join : joins) {
TypeSafeQueryProxyData data = join.getData();
if (data.getProxy() == null) {
throw new IllegalStateException(
format("Data [%s] was added as a join, but does not have a proxy.", data));
}
JoinType effectiveJoinType = data.getEffectiveJoinType();
if (effectiveJoinType == null) {
throw new IllegalArgumentException(
"The getter for ["
+ data.getProxy()
+ "] was called, "
+ "but it was not passed to query.join(object, jointype).");
}
if (data.getPropertyPath() == null) {
appendClassJoin(from, join, params);
} else if (effectiveJoinType != JoinType.None) {
if (isChildOfClassJoin(join)) {
appendPropertyAsClassJoin(from, join, params);
} else {
appendPropertyJoin(from, join, params);
}
}
}
query.appendFrom(from.getHql());
query.addParams(from.getParams());
}
/**
* Adds additional restrictions to the existing from statement, continuing with <code>glue</code>
* if such restrictions exist.
*/
private boolean appendAdditionalRestrictions(
HqlQueryValueImpl from,
TypeSafeQueryJoin<?> join,
String glue,
HqlQueryBuilderParams params) {
HqlQueryValue hqlQueryValue = join.getRestrictions().toHqlQueryValue(params);
String withHql = hqlQueryValue.getHql();
if (withHql.length() > 0) {
from.appendHql(glue).append(withHql);
from.addParams(hqlQueryValue.getParams());
return true;
}
return false;
}
/**
* Check if one of the parents in the hierarchy for this join is a propertyPath-less parent before
* reaching the root.
*
* <p>In Hibernate 5.1.0, the hql is not properly converted to sql when such a case exists.
*/
private boolean isChildOfClassJoin(TypeSafeQueryJoin<?> join) {
TypeSafeQueryProxyData data = join.getData();
while (data.getParent() != null) {
TypeSafeQueryProxyData parent = data.getParent();
if (parent.getParent() == null) {
// root found, no class join in between
return false;
} else if (parent.getPropertyPath() == null) {
// property path -less parent found before root
// this is a class join
return true;
}
data = parent;
}
return false;
}
/**
* Create a join on for a property joined entity which is the child of a class joined entity. This
* is a work around because hibernate doesn't properly convert the hql to sql in this case. (the
* hql looks fine, but the sql throws an SqlGrammarException and the sql property join is missing)
*/
private void appendPropertyAsClassJoin(
HqlQueryValueImpl from, TypeSafeQueryJoin<?> join, HqlQueryBuilderParams params) {
// example: 'left join Product hobj1 on ...'
TypeSafeQueryProxyData data = join.getData();
String alias = data.getAlias();
StringBuilder joinSB =
new StringBuilder(" ")
.append(getJoinTypeString(data.getEffectiveJoinType()))
.append(" ")
.append(helper.getEntityName(data.getPropertyType()))
.append(" ")
.append(alias)
.append(" on ");
if (data.getProxyType().isCollection()) {
String parentId = data.getParent().getIdentifierPath();
// parent.parentIdentifier = child.parentPath.parentIdentifier
String mappedByProperty = helper.getMappedByProperty(data);
joinSB
.append(data.getParent().getAlias())
.append(".")
.append(parentId)
.append(" = ")
.append(alias)
.append(".")
.append(mappedByProperty)
.append(".")
.append(parentId);
} else {
String childId = data.getIdentifierPath();
// child.childIdentifier = parent.childPath.childIdentifier
joinSB
.append(alias)
.append(".")
.append(childId)
.append(" = ")
.append(data.getParent().getAlias())
.append(".")
.append(data.getPropertyPath())
.append(".")
.append(childId);
}
from.appendHql(joinSB.toString());
// append additional "with" restrictions if such exist (continue after identity restriction):
appendAdditionalRestrictions(from, join, " and ", params);
}
private void appendPropertyJoin(
HqlQueryValueImpl from, TypeSafeQueryJoin<?> join, HqlQueryBuilderParams params) {
TypeSafeQueryProxyData data = join.getData();
// example: 'left join fetch' 'hobj1'.'propertyPath' 'hobj2'
from.appendHql(
new StringBuilder(" ")
.append(getJoinTypeString(data.getEffectiveJoinType()))
.append(" ")
.append(data.getParent().getAlias())
.append(".")
.append(data.getPropertyPath())
.append(" ")
.append(data.getAlias())
.toString());
// append additional "with" restrictions if such exist:
appendAdditionalRestrictions(from, join, " with ", params);
}
/** Add class join while validating an on case was specified. */
private void appendClassJoin(
HqlQueryValueImpl from, TypeSafeQueryJoin<?> join, HqlQueryBuilderParams params) {
// example: 'left join Product hobj1 on ...'
TypeSafeQueryProxyData data = join.getData();
from.appendHql(
new StringBuilder(" ")
.append(getJoinTypeString(data.getEffectiveJoinType()))
.append(" ")
.append(helper.getEntityName(data.getPropertyType()))
.append(" ")
.append(data.getAlias())
.toString());
// add the user specified on restrictions, there should at least but some restriction:
if (!appendAdditionalRestrictions(from, join, " on ", params)) {
if (params.isBuildingForDisplay()) {
from.appendHql(" on ????? ");
} else {
throw new IllegalStateException(
String.format(
"Class join without on restriction exists for class [%s]", data.getPropertyType()));
}
}
}