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SQL STUDIO MANAGER TABLE MULTIPLE DELETE UPDATEThe principles involved in writing multiple-table UPDATE statements are quite similar to those used for DELETE: Name all the tables that participate in the operation and qualify column references as necessary. The preceding multiple-table DELETE statements can be rewritten using this syntax as follows: DELETE FROM t1 USING t1 INNER JOIN t2 ON t1.id = t2.id ĭELETE FROM t1, t2 USING t1 INNER JOIN t2 ON t1.id = t2.id ĭELETE FROM t1 USING t1 LEFT JOIN t2 ON t1.id = t2.id WHERE t2.id IS NULL This syntax uses a FROM clause to list the tables from which rows are to be deleted and a USING clause to join the tables that determine which rows to delete. ![]() MySQL supports a second multiple-table DELETE syntax. The analogous DELETE statement to find and remove those rows from t1 uses a LEFT JOIN as well: DELETE t1 FROM t1 LEFT JOIN t2 ON t1.id = t2.id WHERE t2.id IS NULL For example, to identify rows in t1 that have no match in t2, write a SELECT like this: SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.id = t2.id WHERE t2.id IS NULL What if you want to delete nonmatching rows? A multiple-table DELETE can use any kind of join that you can write in a SELECT, so employ the same strategy that you’d use when writing a SELECT that identifies the nonmatching rows. To delete rows from both tables where there are matching id values, name them both after the DELETE keyword: DELETE t1, t2 FROM t1 INNER JOIN t2 ON t1.id = t2.id The syntax also supports deleting rows from multiple tables at once. ![]() Notice that if a column name appears in more than one of the tables, it is ambiguous and must be qualified with a table name. The following statement deletes rows from table t1 where there is a matching id value in table t2: DELETE t1 FROM t1 INNER JOIN t2 ON t1.id = t2.id To write a multiple-table DELETE, name all the tables in a FROM clause and specify the conditions used to match rows in the tables in the WHERE clause. For example, this statement deletes all rows in a table t that have id values greater than 100: DELETE FROM t WHERE id > 100 īut what if you want to delete rows based not on properties inherent in the rows themselves, but rather on their relationship to rows in another table? Suppose that you want to delete from t those rows with id values that are present in or missing from another table t2? To perform a single-table DELETE or UPDATE, you refer only to the columns of one table and thus need not qualify the column names with the table name. These types of statements draw heavily on the concepts used for joins, so be sure you’re familiar with the material discussed earlier in Section 2.8, “Performing Multiple-Table Retrievals with Joins.” SQL STUDIO MANAGER TABLE MULTIPLE DELETE HOW TOThis section describes how to perform multiple-table DELETE and UPDATE operations. Similarly, it’s often useful to update rows in one table using the contents of rows in another table. Sometimes it’s useful to delete rows based on whether they match or don’t match rows in another table. The solution was found here.Learn More Buy 2.11. ![]() I haven’t figured out how to use a variable that contains the tablename. It’s excecuted in the following manner: exec sp_BULK_DELETE_AREA_YEAR ‘2011’ Select from where in < = + TRANĭELETE from where in TRAN SET NOCOUNT ON added to prevent extra result sets from The example uses a stored procedure, but you don’t have to do this. The stored procedure is given a year-variable that is used in the SQL-sentences that selects what has to be deleted.ĬREATE PROCEDURE sp_BULK_DELETE_AREA_YEAR char(4) I use it to avoid getting a transaction log that fills up the harddisk. If you want to simulate bulk-deleting in Microsoft SQL-server this can do the trick. SQL STUDIO MANAGER TABLE MULTIPLE DELETE WINDOWSHector on Disable fair sharing in Windows Server. SQL STUDIO MANAGER TABLE MULTIPLE DELETE INSTALL
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