Database Development Specification

1. Common SQL Writing specifications

• One field takes a row, and a comma precedes the field;
• Keywords need to be aligned

Select

• Each field is exclusive of one row. The comma is written in front of the field.
• If there are multiple tables after the FROM predicate, each table name is one row, and the comma is written in front of the table name.
  
• In the Where condition, if there are multiple and/or conditions, each condition takes one row and and/or at the beginning of the line
• The equal sign "=" leaves a space around.

SELECT  AS col1        AS col2        ,col3   AS col3   FROM table1 t1        ,table2 t2  WHERE t1.col1 = t2.col1AND t1.col2 = t2.col2;

Insert

• Each field occupies one row, and the comma is written in front of the field name.
• The SQL keyword is aligned to the left, and the fields and values correspond to the keyword indents of 2 or 4.

INSERTINTO table1 (   col1  ,col2  ,col3)VALUES (      1  ,‘col2‘  ,‘col3‘);

Update/delete

• Each field occupies one row, and a comma is written in front of the field.
• The equal sign "=" leaves a space around.
• If multiple and/or > * are present in the where condition, each condition occupies one row and and/or at the top of the row.
• Keyword update, set, where, and etc right-aligned (Update/delete)

UPDATE table1    SET‘test‘       ‘test‘  WHERE1;

2. Some development recommendations

• Recommendation: Using prepared statement, you can provide performance and avoid SQL injection.
• Recommendation: In SQL statements, the in contains values should not be too large.
• Recommendation: UPDATE, DELETE statements do not use limit.
• Recommendation: The appropriate type must be used in the where condition to avoid the implicit type conversion of MySQL.

Database Development Specification