Show
13.2.2 DELETE Statement A Single-Table Syntax
The Main Clauses The conditions in the optional If the Multiple-Table Syntax
Privileges You need the Performance When you do not need to know the number of deleted rows, the The speed of delete operations may also be affected by factors discussed in Section 8.2.5.3, “Optimizing DELETE Statements”. To ensure that a given SubqueriesYou cannot delete from a table and select from the same table in a subquery. Partitioned Table Support The For more information and examples, see Section 24.5, “Partition Selection”. Auto-Increment Columns If you delete the row containing the maximum value for an For Modifiers The
Order of Deletion If the
InnoDB Tables If you are deleting many rows from a large table, you may exceed the lock table size for an
No other sessions
can access the tables involved while MyISAM Tables In The
In this scenario, the index blocks associated with the deleted index values become underfilled but are not merged with other index blocks due to the use of If you are going to delete many rows from a table, it might be faster to use Multi-Table Deletes You can specify multiple tables in a For the first multiple-table syntax, only matching rows from the tables listed before the
Or:
These statements use all three tables when searching for rows to delete, but delete matching rows only from tables The preceding examples use
The syntax permits If you use a multiple-table Note If you declare an alias for a table, you must use the alias when referring to the table:
Table aliases in a multiple-table Correct:
Incorrect:
Table aliases are also supported for single-table Which of the following statements describes the reason you would want to record a macro with absolute references rather than relative?Which of the following statements describes the reason you would want to record a macro with absolute references rather than relative? You want to preserve the integrity of any cells referenced by formulas in the macro.
Which of the following statements accurately describe the default selection for AutoSum?Which of the following statements accurately describes the default selection for AutoSum? By default, AutoSum calculates the total from the adjacent cell through the first nonnumeric cell.
Which of the following procedures is not a way to sort a table by the contents of one column *?You cannot sort a table in alphabetical or numerical order for one column, and by conditional formatting for another column, at the same time.
Which of the following functions automatically counts cells that meet a specific condition?The COUNTIF Function[1] will count the number of cells that meet a specific criterion.
|