In MySQL select INTO and INSERT into select two table copy statements

Select INTO and INSERT into select two table copy statements
Insert is a common statement in T-SQL, insert into table (Field1,field2,...) VALUES (value1,value2,...)
This form is essential in application development. But in the development, testing process, we often encounter the need for table replication,
If you copy part of a table1 data to a table2, or copy the entire table1 to table2, we
You will use the SELECT INTO and INSERT into the Select table to copy the statement.

1.INSERT into SELECT statement
Statement form: Insert into Table2 (field1,field2,...) Select Value1,value2,... from Table1
The target table Table2 must exist, because the target table Table2 already exists, so in addition to inserting fields from the source table Table1,
You can also insert constants. Examples are as follows:
--1. Create a test table

The code is as follows	Copy Code
Create TABLE Table1     (         a varchar (a),         b varchar (a),         C varchar (         CONSTRAINT [pk_table1] PRIMARY KEY CLUSTERED          (             a ASC        )    ) on [PRIMARY] Create TABLE Table2 ( A varchar (10), C varchar (10), d int, CONSTRAINT [Pk_table2] PRIMARY KEY CLUSTERED ( A ASC ) ) on [PRIMARY] Go

--2. Create test data

The code is as follows

Copy Code

Insert into Table1 values (' Zhao ', ' ASDs ', ', ')     Insert into Table1 values (' money ', ' ASDs ', ')      INSERT into Table1 values (' Sun ', ' ASDs ', ', ')     insert into Table1 values (' Lee ', ' ASDs ', null)     Go     select * to Table2    --3.insert into Select statement Copy table Data     Insert into Table2 (A, C, D) Select a,c,5 from Table1     go    --4. Show updated Results     select * from Table2     go     --5. Delete Test table     drop table Table1     drop table Table2

2.SELECT into from statement
Statement form: SELECT vale1, value2 into Table2 from Table1
The target table Table2 is not present because the table Table2 is created automatically when inserting.
and copies the specified field data in the Table1 to the Table2. Example below

--1. Create a test table

code is as follows	copy code
Create TABLE Table1     (         a varchar (),   & nbsp;     b varchar (a),         C varchar (a),         CONSTRAINT [pk_table1] PRIMARY KEY CLUSTERED          (             a ASC         )    ) on [PRIMARY]     go   & nbsp.

--2. Create test data
   

code is as follows

copy code

INSERT into Table1 values (' Zhao ', ' ASDs ', ', ')     insert INTO Table1 values (' money ', ' ASDs ', ' m ')     Insert into Table1 values (' Sun ', ' ASDs ', ')      Insert into Table1 values (' Lee ', ' ASDs ', null)     go    --3.select into The FROM statement creates the table Table2 and copies the data     select A,c into Table2 from Table1     go  & nbsp; --4. Show updated Results     select * from Table2     go    -- 5. Delete Test table     drop table Table1     drop table Table2