![]() In addition, the corresponding columns of the first select statement must have. You can easily adapt it to any database supported by SQLAlchemy, like: PostgreSQL MySQL SQLite Oracle Microsoft SQL Server, etc. If more than one CTEquerydefinition is defined, the query definitions must be joined by one of these set operators: UNION ALL, UNION, EXCEPT, or INTERSECT. The select lists of the select statements must have the same number of columns. You have not provided SQL script you used in your example so all I can do is to suggest checking your installation. For more information, see the Remarks section and CREATE VIEW (Transact-SQL). Mysql> CREATE VIEW `zztestview`.`test21614` AS > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 UNION Syntax SELECT columnname (s) FROM table1 UNION SELECT columnname (s) FROM table2 UNION ALL Syntax The UNION operator selects only distinct values by default. vwPurchParent as WITH cte AS ( SELECT a.Id, a.parentId, a.name, a.IsLedger FROM tblChartOfAcc a WHERE Id 1 UNION ALL SELECT a.Id, a.parentid, a.Name, a.IsLedger FROM tblChartOfAcc a JOIN cte c ON a.parentId c. Description: If you set up a database with default collation different from default of the character set, then string literals, cast and convert gives wrong default collation for that column when you create a view (possibly other functions as well). To create the view explicitly in a given database, use dbname.viewname syntax to qualify the view name with the database name: CREATE VIEW test.v AS SELECT FROM t Unqualified table or view names in the SELECT statement are also interpreted with respect to the default database. ![]() If you dont specify ALL or DISTINCT, it will depend on the uniondefaultmode. ![]() Your MySQL connection id is 1 to server version: 5.0.23-log Create a new View by clicking on the Tables icon in the Databases column of the main document window and then clicking on the Create View icon in the Tasks section. You can use UNION with explicitly specifying UNION ALL or UNION DISTINCT. Right now it works, but my question is, is this a good idea? The requirement asks that I only provide a script (or a view) and not a stored procedure, I think this would be better with an SP since I could just do a quick IF EXIST() statement for each of the table and just check if the parameter user exists in any of the table, but they really wanted it to be only a script they could check (and no using of variables).Ĭan you guys give me advice on a better way of doing this requirement, that would have less impact on performance since this may not be the optimized solution for this requirement.Tonci Grgin Amit, since I found nothing in the changelog ( ) I tested with version 5.0.23 and a coleague tested 5.0.24. From a performance point of view I would structure the query slightly differently: SELECT DISTINCT userID FROM ( SELECT userID FROM transactiontable1 UNION ALL SELECT userID FROM transactiontable2 UNION ALL SELECT userID FROM transactiontable3. For columns used elsewhere in the SELECT statement, you must have the SELECT privilege. So here's my query for the view: SELECT DISTINCT user_ID The CREATE VIEW statement requires the CREATE VIEW privilege for the view, and some privilege for each column selected by the SELECT statement. I suggested using a VIEW that will contain all the users that are already referenced, then the DEV team could just SELECT through that table to find out if the data they're looking for is there or not, I have a requirement to check if a specific user is already being referenced to one of our transaction tables (we have around 10 transaction tables). union sql-view Share Improve this question Follow asked at 8:42 No Idea For Name 11.4k 10 41 68 Add a comment 1 Answer Sorted by: 3 As you might already know, the second method is faster because unlike the first it does not bring get all results from all three tables and then filter.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |