Learning notes for MySQL required: 1

Learning notes for MySQL required: 1 # select a database

USE mysql

# Back to the list of available databases

SHOW DATABASES

# Return the available tables in the current database

SHOW TABLES

# Return table columns

Show columns from db

# Display creation statements for a specific database

Show create database mysql

# Display a wide range of server status information

SHOW STATUS

# Display the security permissions of authorized users

SHOW GRANTS

Multiple SQL statements must be separated by semicolons.

SQL statements are case-insensitive and often capitalized.

Use DISTINCT to retrieve different rows. only different values are returned.

LIMIT result, LIMIT clause

LIMIT 5 returns no more than five rows.

LIMIT 3 and 4 rows starting from row 3

LIMIT 4 OFFSET 3 (the result is the same as above) [supported after MySQL5]

Order by clause sorting

DESC/ASC specify the sorting direction

WHERE clause. order by is located after WHERE.

Operator	Description
=	Equal
<>	Not equal
! =	Not equal
<	Less
<=	Less than or equal
>	Greater
> =	Greater than or equal
BETWEEN	Between two specified values

NULL

WHERE *** is null check whether the field has a NULL value.

And or operator.

The IN operator is used to specify the condition range. multiple valid values are separated by commas.

NOT negative operator, which can be used to reverse the IN, BETWEEN, and EXISTS clauses.