Special SQL usage in MySQL

As database software, mysql and Oracle are both based on standard SQL, but there are still some similarities and differences. Here we will list the differences:

1. limit (note that the row number starts from 0)

Limit 4th: the first digit indicates the row number, and the second digit indicates the number of rows of data returned. This indicates that four rows of data are returned starting from the second row (the row number starts from 0.

Limit 3 offset 4: Take 3 rows from Row 4, where the row number starts from 0

2. where col = 'abc' is the same as where col = 'abc'. Matching is case-insensitive, including =, <>

3. Character concatenation. function: concat ([Character List])

4. functions such as avg, max, min, and sum ignore NULL columns.

5. insert multiple entries:

You can use:

Insert into table (col1, col2)

Values (p_11, p_12), (p_21, p_22 );