Tb_name: Table name; column: field, list name; CODE: Condition;
Query statement: SELECT;
(1) SELECT * from Tb_name;
(2) SELECT COLUMN from Tb_name;
(3) SELECT COLUMN from Tb_name WHERE column1=. and/or column2=.;
(4) SELECT COLUMN from Tb_name WHERE (column1=. and/or column2=..) Or/and column3=.;
DML (Data Manipulation language) statement: INSERT, delete,update;
Manipulate the data.
INSERT:
(1) INSERT into Tb_name (Column1,column2,)
VALUES (..,..);
(2) INSERT into Tb_name (Column1,column2,)
VALUES (.,..), (...),.. ...;
Column not in general default to null;
DELETE:
(1) DELETE from Tb_name;
(2) DELETE from Tb_name WHERE CODE1;
(3) DELETE from Tb_name WHERE CODE1 and/or CODE2;
UPDATE:
(1) UPDATE tb_name SET column1=value1;
(2) UPDATE tb_name SET column1=value1, column2=value2 ...;
(3) UPDATE tb_name SET column1=value1 WHERE CODE1;
(4) UPDATE tb_name SET column1=value1, column2=value2 ... WHERE CODE1 and/or CODE2;
SQL Basics (1)