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Roman
Asked: 2010-03-04 02:40:13 +0800 CST

How to create a table in MySQL with automatic numeration of rows?

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I just want to have a table in which a first column is a monotonically increasing unique integer number. For example, if I have a table with 5 rows the indexes of the rows should be 1,2,3,4,5. And if I add a new row it gets index 6.

I am alway confused with this things because there are many related options: "auto_increment", "primary key", "unique", "index". What should I use?

mysql database autoincrement

1 Answers

  1. Best Answer
    CREATE TABLE test (
     id INT NOT NULL AUTO_INCREMENT,
     name CHAR(30) NOT NULL,
     PRIMARY KEY (id)
 );

    auto_increment: This value will automatically increase.

    primary key: This is the column which holds the first, and probably most logical, sort order. Almost always this means that it's unique.

    index: This column is one which might be chosen as a sort order. Any column or combination of columns can be indexed, not just the primary key.

    unique: This is a special index, where each value is going to appear only once.

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