4.2.13. MySQL query data

发布时间 :2025-10-25 12:31:19 UTC      

The MySQL database uses SQL SELECT statements to query data.

You can query the data in the database from the mysql > command prompt window, or query the data through the PHP script.

Grammar

The following is the common SELECT syntax for querying data in an MySQL database:

SELECT column_name,column_name
FROM table_name
[WHERE Clause]
[LIMIT N][ OFFSET M]
  • You can use one or more tables in the query, split the tables with a comma (,), and use the WHERE Statement to set the query conditions.

  • The SELECT command can read one or more records.

  • You can use an asterisk (*) instead of other fields, and the SELECT statement returns all the field data of the table

  • You can use the WHERE statement to include any condition.

  • You can use the LIMIT property to set the number of records returned.

  • You can specify the data offset to start the query with the SELECT statement through OFFSET. The offset is 0 by default.

Get data from the command prompt

For the following example, we will get the MySQL data table through the SQL SELECT command runoob_tbl Data of:

Example

The following example returns a data table runoob_tbl All records of:

Read the data table:

select\*fromrunoob_tbl;

Output result:

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Principles, Technologies, and Methods of Geographic Information Systems  102

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