enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Hierarchical and recursive queries in SQL - Wikipedia

    en.wikipedia.org/wiki/Hierarchical_and_recursive...

    A common table expression, or CTE, (in SQL) is a temporary named result set, derived from a simple query and defined within the execution scope of a SELECT, INSERT, UPDATE, or DELETE statement. CTEs can be thought of as alternatives to derived tables ( subquery ), views , and inline user-defined functions.

  3. Rollback (data management) - Wikipedia

    en.wikipedia.org/wiki/Rollback_(data_management)

    SQL refers to Structured Query Language, a kind of language used to access, update and manipulate database. In SQL, ROLLBACK is a command that causes all data changes since the last START TRANSACTION or BEGIN to be discarded by the relational database management systems (RDBMS), so that the state of the data is "rolled back" to the way it was before those changes were made.

  4. Microsoft Access - Wikipedia

    en.wikipedia.org/wiki/Microsoft_Access

    One can set up joins by clicking and dragging fields in tables to fields in other tables. Access allows users to view and manipulate the SQL code if desired. Any Access table, including linked tables from different data sources, can be used in a query. Access also supports the creation of "pass-through queries".

  5. Access Database Engine - Wikipedia

    en.wikipedia.org/wiki/Access_Database_Engine

    Bi-directional replication with MS SQL Server. Microsoft Access versions from Access 2000 to Access 2010 included an "Upsizing Wizard" which could "upsize" (upgrade) a Jet database to "an equivalent database on SQL Server with the same table structure, data, and many other attributes of the original database". Reports, queries, macros and ...

  6. Cursor (databases) - Wikipedia

    en.wikipedia.org/wiki/Cursor_(databases)

    For example, Microsoft SQL Server implements cursors by creating a temporary table and populating it with the query's result set. If a cursor is not properly closed (deallocated), the resources will not be freed until the SQL session (connection) itself is closed. This wasting of resources on the server can lead to performance degradations and ...

  7. Select (SQL) - Wikipedia

    en.wikipedia.org/wiki/Select_(SQL)

    Title Authors ----- ----- SQL Examples and Guide 4 The Joy of SQL 1 An Introduction to SQL 2 Pitfalls of SQL 1 Under the precondition that isbn is the only common column name of the two tables and that a column named title only exists in the Book table, one could re-write the query above in the following form:

  8. SQL syntax - Wikipedia

    en.wikipedia.org/wiki/SQL_syntax

    Title Authors ----- ----- SQL Examples and Guide 4 The Joy of SQL 1 An Introduction to SQL 2 Pitfalls of SQL 1 Under the precondition that isbn is the only common column name of the two tables and that a column named title only exists in the Book table, one could re-write the query above in the following form:

  9. Surrogate key - Wikipedia

    en.wikipedia.org/wiki/Surrogate_key

    To discover such errors, one must perform a query that uses a left outer join between the table with the foreign key and the table with the primary key, showing both key fields in addition to any fields required to distinguish the record; all invalid foreign-key values will have the primary-key column as NULL. The need to perform such a check ...