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How to 'insert if not exists' in MySQL?

... Solution: INSERT INTO `table` (`value1`, `value2`) SELECT 'stuff for value1', 'stuff for value2' FROM DUAL WHERE NOT EXISTS (SELECT * FROM `table` WHERE `value1`='stuff for value1' AND `value2`='stuff for value2' LIMIT 1) Explanation: The innermost query SELECT *...
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Mysql: Select rows from a table that are not in another

How to select all rows in one table that do not appear on another? 8 Answers 8 ...
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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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SELECT INTO Variable in MySQL DECLARE causes syntax error?

I´d like to SELECT a single value into a variable. I´d tried to following: 11 Answers ...
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MySQL maximum memory usage

...e to know how it is possible to set an upper limit on the amount of memory MySQL uses on a Linux server. 6 Answers ...
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What is the strict aliasing rule?

...mited buffer doesn't necessarily help. So how do I get around this? Use a union. Most compilers support this without complaining about strict aliasing. This is allowed in C99 and explicitly allowed in C11. union { Msg msg; unsigned int asBuffer[sizeof(Msg)/sizeof(unsigned int)]; }; ...
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Why do we need C Unions?

When should unions be used? Why do we need them? 18 Answers 18 ...
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Select all columns except one in MySQL?

I'm trying to use a select statement to get all of the columns from a certain MySQL table except one. Is there a simple way to do this? ...
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How to best display in Terminal a MySQL SELECT returning too many fields?

... Terminate the query with \G in place of ;. For example: SELECT * FROM sometable\G This query displays the rows vertically, like this: *************************** 1. row *************************** Host: localhost Db: mydatabase1 ...
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How do I connect to a MySQL Database in Python?

...ueries you need cur = db.cursor() # Use all the SQL you like cur.execute("SELECT * FROM YOUR_TABLE_NAME") # print all the first cell of all the rows for row in cur.fetchall(): print row[0] db.close() Of course, there are thousand of possibilities and options; this is a very basic example. Y...