select from multiple tables

Mysql supports cross-table delete multi-table record bitsCN.com a few days ago, I wrote a summary of Mysql cross-table update. today we will look at cross-table deletion. After Mysql4.0, mysql began to support cross-table delete. Mysql can delete multiple table records in an SQL statement at the same time, or delete records in a table based on the relationship between multiple

How can I locate multiple mysql tables in which the content is sorted by the last update time mysql nbsp; how can I locate multiple tables in which the content is sorted by the last update time and the fields are the same, only tables with different content names: aaa, bbb,

For example, two tables, apply and activityapply, have the openid field and the idac_id of activity. Now we need to query openid and all records with openid in the apply table. How can we write an SQL statement, for example, two tables? the openid and activity id ac_id fields in the apply and activity apply tables now need to be queried in the apply table and all

When multiple users operate data tables in php at the same time and perform insert or update operations on the same table, the same data may occur many times or some strange problems, the mysql lock table mechanism can be used for queuing to solve this problem. before inserting data in php, the lock table // locktalbewrite nbsp; nbsp solves the problem of simultaneous data table operation by

Find all columns with the same column name (regardless of type and accuracy) from different tables. Note that the number 3 in the last column is the number of tables to be queried. Select a. Name, count (1) as TT from syscolumns A, sysobjects B Where a. ID = B. ID and B. xtype = 'U' and B. Name in ('table _ 1', 'table _ 2', 'table _ 3 ') Group by A. Name Havi

that the Enterprise Library in the call to Oracle when returning a result set of the time to know this name cur_out, if the change into something else is not (I tried, changed to another name is really wrong, the Enterprise Library does not know), specifically why, I do not know. C # Calls://CREATE Database objectsDatabase db = Databasefactory.createdatabase ("Oracle");Construct cmdDbCommand dbcmd = db. Getstoredproccommand ("P_sel_topcount");Adding parameters, and without setting the cursor pa

UPDATE multiple tables in OracleThe following methods can be implemented:One is:Update table1Set (field1, field2. ..) =(Select Field1, field2 ....From table2Where table1.field1 = table2.field1)Where table1.field1 in (select field1 from table2) Two types are:Associate fields table1 and table2 with the PRimary key or Uni

During Oracle operations, data is often inserted into multiple different tables at the same time. This statement is very suitable. "All" indicates a non-short-circuit operation, that is, if the First condition is met, you must run the following command to check whether other conditions are met. However, if the First condition is found for the short-circuit operation, the operation will not proceed downward.

In order to be simple and describe the main content, some secondary HTML content is relatively simple. When the website has multiple content to be displayed on a page, you can use one display and submit on the page. In this example, there are two data tables (News, CTM) and one home page (index. php ); One submission page (index_pub.php; and one package page (index_view.php) A child page (view_d.php ). ----

qualifying data from a. For example: insert into C (C.AID,C.A,C.B, C.C) select a.id,a.a,a.b,a.c from a where a.id 5000000 Execution completes approximately 40 seconds The data that matches the criteria is queried from table B and inserted into C. For example:INSERT into SELECT from WHERE b.aid5000000onKEYUPDATE c.d= Values(C.D), C.E=values(C.E), c.f=values(C.F)Approximately more than 50 se

ASP tutorial. NET C # import Excel into the MSSQL SQL database tutorial and support multiple sheet tables' Workaround one Objsheet = (excel._worksheet) objsheets.get_item (Sheets); ' Instance code for (int i = 0; i { for (int j = 0; J { Objsheet.cells[i + 2, j + 1] = Dtdata.rows[i][j];}} ' Its It instance Excel data is imported into SQL Server: SE