Chapitre 14. HQL: Langage de requêtage d'Hibernate. Hibernate uses a powerful query language (HQL) that is similar in appearance to SQL.
Compared with SQL, however, HQL is fully object-oriented and understands notions like inheritance, polymorphism and association. You can also assign aliases to associated entities or to elements of a collection of values using a join. Oracle Update with Join – Revisited. I’ve had a lot of feedback on my Oracle Update with Join post.
The most common problem people have encountered with this approach is the dreaded “SQL Error: ORA-01779: cannot modify a column which maps to a non key-preserved table”. Tom Kyte has a detailed explanation of this at Ask Tom. However, I thought I would take a moment to address my example scenario.
Java. Console. SQL Functions. SQL functions are built into Oracle Database and are available for use in various appropriate SQL statements.
Do not confuse SQL functions with user-defined functions written in PL/SQL. If you call a SQL function with an argument of a datatype other than the datatype expected by the SQL function, then Oracle attempts to convert the argument to the expected datatype before performing the SQL function. Regular Expressions Reference - Basic Syntax. The regular expressions reference on this website functions both as a reference to all available regex syntax and as a comparison of the features supported by the regular expression flavors discussed in the tutorial.
The reference tables pack an incredible amount of information. To get the most out of them, follow this legend to learn how to read them. The tables have six columns for each regular expression feature. The first four explain the feature.