How to query the number of fields in mysql

Query method: 1. Use the DESCRIBE statement to display the table structure, with the syntax "DESCRIBE table name;". The total number of record rows output is the number of fields; 2. Use the count() function to count the system table "information_schema. COLUMNS" to query the number of fields by specifying the number of data items.

The operating environment of this tutorial: windows7 system, mysql8 version, Dell G3 computer.

There are two ways to query the number of fields in a MySQL table

Method 1: Use the DESCRIBE statement

DESCRIBE will display the field information of the table in the form of a table, including field name, field data type, whether it is the primary key, whether there is a default value, etc. The syntax format is as follows:

DESCRIBE 表名;

can be abbreviated as:

DESC 表名;

The total number of record rows output is the number of fields.

Example:

##Method 2: Through the system table information_schema.`COLUMNS` (supported by mysql5 and above)

Query the number of fields by using the count() function to count the number of specified data items in the system table "information_schema.COLUMNS".

Syntax:

SELECT count(1) from information_schema.COLUMNS WHERE table_schema='库名' and table_name='表名';

• table_schema: Database name

##table_name: Table name
Example:

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