Difference between Select Into and Insert Into from old table? - sql

Question

What is difference between these in terms of constraints *keys* etc.
Select Into Statement
SELECT column1, column2, someInt, someVarChar
INTO ItemBack1
FROM table2
WHERE table2.ID = 7
Insert Into Statement
INSERT INTO table1 ( column1, column2, someInt, someVarChar )
SELECT table2.column1, table2.column2,
FROM table2
WHERE table2.ID = 7
and also
Create table ramm as select * from rammayan
Edit 1:
Database SQL Server 2008

Answer 1

I'm going to assume MySQL here.
The first two are identical, as the documentation states.
The third statement allows for both table creation and population, though your syntax is wrong up there; look at the right syntax for more info.
Update
It's SQL Server =p
SELECT column1, column2, someInt, someVarChar
INTO ItemBack1
FROM table2
WHERE table2.ID = 7
The first statement will automatically create the ItemBack1 table, based on table2.
INSERT INTO table1 ( column1, column2, someInt, someVarChar )
SELECT table2.column1, table2.column2,
FROM table2
WHERE table2.ID = 7
The second second statement requires that table1 already exists.
See also: http://blog.sqlauthority.com/2007/08/15/sql-server-insert-data-from-one-table-to-another-table-insert-into-select-select-into-table/
If there's any difference in constraints, it would be because the second statement depends on what you have already created (and if the table is populated, etc.).
Btw, the third statement is Oracle(tm) and is the same as the first statement.

Answer 2

There are some very important differences between SELECT INTO and INSERT.
First, for the INSERT you need to pre-define the destination table. SELECT INTO creates the table as part of the statement.
Second, as a result of the first condition, you can get type conversion errors on the load into the table using INSERT. This cannot happen with a SELECT INTO (although the underlying query could produce an error).
Third, with a SELECT INTO you need to give all your columns names. With an INSERT, you do not need to give them names.
Fourth, SELECT INTO locks some of the metadata during the processing. This means that other queries on the database may be locked out of accessing tables. For instance, you cannot run two SELECT INTO statements at the same time on the same database, because of this locking.
Fifth, on a very large insert, you can sometimes see progress with INSERT but not with SELECT INTO. At least, this is my experience.
When I have a complicated query and I want to put the data into a table, I often use:
SELECT top 0 *
INTO <table>
FROM <query>
INSERT INTO <table>
SELECT * FROM <query>

Answer 3

Select Into ->Creates the table on the fly upon select execution
while
Insert Into ->Presumes that the Table DB already exist
lastly
Create, simply creates the table from the return result of the query

Answer 4

I don't really understand your question. Let's try:
The 1st one selects the value of the columns "someVarChar" into a variable called "ItemBack1". Depending on your SQL-Server (mysql/oracle/mssql/etc.) you can now do some logic with this var.
The 2nd one inserts the result of
SELECT table2.column1, table2.column2, 8, 'some string etc.'
FROM table2
WHERE table2.ID = 7
into the table1 (Copy)
And the 3rd creates a new table "ramm" as a copy of the table "rammayan"

Answer 5

Generally speaking
Each one has its own particularities, one creates a temporary table, other uses a previously existing table and the third one creates a new table with exact same estructure and formatting
SELECT…INTO creates a new table in the default filegroup and inserts the resulting rows from the query into it
INSERT INTO: fills an already existing table
INSERT...INTO
The third option is known as CTAS (Create Table As Select) do a search and you will get tons of usefull links. Basically it creates a table, not a temporary one, with the structure and types used on the SELECT statement.
I wanted to add some more links but as I'm a new user I'm only allowed to post 2 links to prevent spam.

Answer 6

INSERT INTO SELECT inserts into an existing table.
SELECT INTO creates a new table and puts the data in it.
All of the columns in the query must be named so each of the columns in the table will have a name. This is the most common mistake I see for this command.
The data type and nullability come from the source query.
If one of the source columns is an identity column and meets certain conditions (no JOINs in the query for example) then the column in the new table will also be an identity.
INSERT INTO SELECT
CREATE TABLE ExistingTableName1 (ColumnName VARCHAR(255));
GO
INSERT
INTO ExistingTableName1
SELECT ColumnaName
FROM ExistingTableName2;
GO
SELECT INTO INSERT
SELECT ColumnName INTO NewTableName
FROM ExistingTableName1;
GO

Answer 7

The SQL SELECT INTO Statement
The SELECT INTO statement copies data from one table into a new table.
SELECT INTO Syntax
SELECT column1, column2, column3, ...
INTO newtable [IN externaldb]
FROM oldtable
WHERE condition;
The new table will be created with the column-names and types as defined in the old table. You can create new column names using the AS clause.
The SQL INSERT INTO SELECT Statement
The INSERT INTO SELECT statement copies data from one table and inserts it into another table.
INSERT INTO SELECT Syntax
INSERT INTO table2 (column1, column2, column3, ...)
SELECT column1, column2, column3, ...
FROM table1
WHERE condition;
INSERT INTO SELECT requires that data types in source and target tables match
The existing records in the target table are unaffected