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How to use GROUP BY to concatenate strings in MySQL?
... id, GROUP_CONCAT(name SEPARATOR ' ') FROM table GROUP BY id;
http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat
From the link above, GROUP_CONCAT: This function returns a string result with the concatenated non-NULL values from a group. It returns NULL if there ...
Alter a MySQL column to be AUTO_INCREMENT
...ber between parenthesis does exactly nothing (well ok, almost nothing) for MySQL integer types. The only thing that may be influenced by the number is the display width, and it is up to the client to do that. But don't be deceived and think that it works like it does for VARCHAR and DECIMAL types - ...
MySQL combine two columns into one column
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My guess is that you are using MySQL where the + operator does addition, along with silent conversion of the values to numbers. If a value does not start with a digit, then the converted value is 0.
So try this:
select concat(column1, column2)
Two way...
Row count with PDO
... get the row count using PDO in PHP? Before using PDO, I just simply used mysql_num_rows .
23 Answers
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How to set initial value and auto increment in MySQL?
How do I set the initial value for an "id" column in a MySQL table that start from 1001?
10 Answers
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What's the difference between comma separated joins and join on syntax in MySQL? [duplicate]
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This answer is not correct. In the MySQL manual on the page dev.mysql.com/doc/refman/5.5/en/join.html it states: "However, the precedence of the comma operator is less than that of INNER JOIN, CROSS JOIN, LEFT JOIN, and so on. If you mix comma joins with the o...
How to reset AUTO_INCREMENT in MySQL?
...ccurs and the current sequence value is not changed.
See How to Reset an MySQL AutoIncrement using a MAX value from another table? on how to dynamically get an acceptable value.
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When should I use UNSIGNED and SIGNED INT in MySQL?
When should I use UNSIGNED and SIGNED INT in MySQL ?
What is better to use or this is just personal prefernce ?
Because I've seen it used like this;
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Boolean vs tinyint(1) for boolean values in MySQL
What column type is best to use in a MySQL database for boolean values? I use boolean but my colleague uses tinyint(1) .
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How can I add comments in MySQL?
I want to add comment in SQL code. How can I do this? I'm using MySQL.
6 Answers
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