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How to copy data from one table to another new table in MySQL?

...hat you want: INSERT INTO table2 (st_id,uid,changed,status,assign_status) SELECT st_id,from_uid,now(),'Pending','Assigned' FROM table1 If you want to include all rows from table1. Otherwise you can add a WHERE statement to the end if you want to add only a subset of table1. I hope this helps. ...
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How do I check if a column is empty or null in MySQL?

... This will select all rows where some_col is NULL or '' (empty string) SELECT * FROM table WHERE some_col IS NULL OR some_col = ''; share | ...
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How to declare a variable in a PostgreSQL query

...ows you to return a table of temporary values. WITH master_user AS ( SELECT login, registration_date FROM users WHERE ... ) SELECT * FROM users WHERE master_login = (SELECT login FROM master_user) AND (SELECT registration_date FROM ma...
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In MySQL, how to copy the content of one table to another table within the same database?

... INSERT INTO TARGET_TABLE SELECT * FROM SOURCE_TABLE; EDIT: or if the tables have different structures you can also: INSERT INTO TARGET_TABLE (`col1`,`col2`) SELECT `col1`,`col2` FROM SOURCE_TABLE; EDIT: to constrain this.. INSERT INTO TARGET_TAB...
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How to delete duplicate rows in SQL Server?

... are deleted (or updated), therefore just change the DELETE FROM CTE... to SELECT * FROM CTE: WITH CTE AS( SELECT [col1], [col2], [col3], [col4], [col5], [col6], [col7], RN = ROW_NUMBER()OVER(PARTITION BY col1 ORDER BY col1) FROM dbo.Table1 ) DELETE FROM CTE WHERE RN > 1 DEMO (re...
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Rails 3: Get Random Record

...You can use the following trick on an indexed column (PostgreSQL syntax): select * from my_table where id >= trunc( random() * (select max(id) from my_table) + 1 ) order by id limit 1; share | ...
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Is there any difference between GROUP BY and DISTINCT

...CT and distinct by UNION cause an oracle error, but GROUP BY worked; I was selecting only 1 column from a view and not using any aggregation; I'm still baffled why it required it, but it does confirm there is some difference in the execution. As others point out, it also lets you GROUP BY columns no...
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MySQL get row position in ORDER BY

... Use this: SELECT x.id, x.position, x.name FROM (SELECT t.id, t.name, @rownum := @rownum + 1 AS position FROM TABLE t JOIN (SELECT @rownum := 0) r ORDER BY t.name)...
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'IF' in 'SELECT' statement - choose output value based on column values

... SELECT id, IF(type = 'P', amount, amount * -1) as amount FROM report See http://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html. Additionally, you could handle when the condition is null. In the case of...
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How do you connect to multiple MySQL databases on a single webpage?

...d); $dbh2 = mysql_connect($hostname, $username, $password, true); mysql_select_db('database1', $dbh1); mysql_select_db('database2', $dbh2); Then to query database 1 pass the first link identifier: mysql_query('select * from tablename', $dbh1); and for database 2 pass the second: mysql_query...