static {
StringBuilder builder = new StringBuilder();
builder.append("(?<=from)"); // from as starting delimiter
builder.append("(?: )+"); // at least one space separating
builder.append(IDENTIFIER_GROUP); // Entity name, can be qualified (any
builder.append("(?: as)*"); // exclude possible "as" keyword
builder.append("(?: )+"); // at least one space separating
builder.append("(\\w*)"); // the actual alias
ALIAS_MATCH = compile(builder.toString(), CASE_INSENSITIVE);
builder = new StringBuilder();
builder.append("(select\\s+((distinct )?(.+?)?)\\s+)?(from\\s+");
builder.append(IDENTIFIER);
builder.append("(?:\\s+as)?\\s+)");
builder.append(IDENTIFIER_GROUP);
builder.append("(.*)");
COUNT_MATCH = compile(builder.toString(), CASE_INSENSITIVE);
Map<PersistentAttributeType, Class<? extends Annotation>> persistentAttributeTypes =
new HashMap<PersistentAttributeType, Class<? extends Annotation>>();
persistentAttributeTypes.put(ONE_TO_ONE, OneToOne.class);
persistentAttributeTypes.put(ONE_TO_MANY, null);
persistentAttributeTypes.put(MANY_TO_ONE, ManyToOne.class);
persistentAttributeTypes.put(MANY_TO_MANY, null);
ASSOCIATION_TYPES = Collections.unmodifiableMap(persistentAttributeTypes);
}
/**
* Adds {@literal order by} clause to the JPQL query.
*
* @param query
* @param sort
* @param alias
* @return
*/
public static String applySorting(String query, Sort sort, String alias) {
Assert.hasText(query);
if (null == sort || !sort.iterator().hasNext()) {
return query;
}
StringBuilder builder = new StringBuilder(query);
if (!ORDER_BY.matcher(query).matches()) {
builder.append(" order by ");
} else {
builder.append(", ");
}
Set<String> aliases = getOuterJoinAliases(query);
for (Order order : sort) {
builder.append(getOrderClause(aliases, alias, order)).append(", ");
}
builder.delete(builder.length() - 2, builder.length());
return builder.toString();
}
/**
* Returns the query string to execute an exists query for the given id attributes.
*
* @param entityName the name of the entity to create the query for, must not be {@literal null}.
* @param countQueryPlaceHolder the placeholder for the count clause, must not be {@literal null}.
* @param idAttributes the id attributes for the entity, must not be {@literal null}.
* @return
*/
public static String getExistsQueryString(
String entityName, String countQueryPlaceHolder, Iterable<String> idAttributes) {
StringBuilder sb =
new StringBuilder(String.format(COUNT_QUERY_STRING, countQueryPlaceHolder, entityName));
sb.append(" WHERE ");
for (String idAttribute : idAttributes) {
sb.append(String.format(EQUALS_CONDITION_STRING, "x", idAttribute, idAttribute));
sb.append(" AND ");
}
sb.append("1 = 1");
return sb.toString();
}
/**
* Creates a where-clause referencing the given entities and appends it to the given query string.
* Binds the given entities to the query.
*
* @param <T>
* @param queryString
* @param entities
* @param entityManager
* @return
*/
public static <T> Query applyAndBind(
String queryString, Iterable<T> entities, EntityManager entityManager) {
Assert.notNull(queryString);
Assert.notNull(entities);
Assert.notNull(entityManager);
Iterator<T> iterator = entities.iterator();
if (!iterator.hasNext()) {
return entityManager.createQuery(queryString);
}
String alias = detectAlias(queryString);
StringBuilder builder = new StringBuilder(queryString);
builder.append(" where");
int i = 0;
while (iterator.hasNext()) {
iterator.next();
builder.append(String.format(" %s = ?%d", alias, ++i));
if (iterator.hasNext()) {
builder.append(" or");
}
}
Query query = entityManager.createQuery(builder.toString());
iterator = entities.iterator();
i = 0;
while (iterator.hasNext()) {
query.setParameter(++i, iterator.next());
}
return query;
}