I am creating a table using the CREATE TABLE AS Statement. Script looks like this :
CREATE TABLE table2
AS
SELECT column1, column2, ..., columnN
FROM table1
WHERE ROWNUM <= 50;
My question is, can I create additional columns on table2 that don't exist in table1 inside the CREATE TABLE AS Statement or do I have to resort to ALTER afterwards?
EDIT: For example table1 contains ID, FULLNAME, STATUS and I wanna add a column somewhere in between called AGE
I am using Oracle Sql
You can add whatever you'd like to the SELECT
CREATE TABLE table2
AS
SELECT column1, column2, ..., columnN,
trunc(months_between(birth_date,sysdate)/12) age,
'Some string' another_column
FROM table1
WHERE ROWNUM <= 50;
Related
for my intention I have to select a table to select columns from dependent on the column-value of an already given table.
First I thought about a CASE construct, if this is possible with sqlite.
SELECT * FROM
CASE IF myTable.column1 = "value1" THEN (SELECT * FROM table1 WHERE ...)
ELSE IF myTable.column1 = "value2" THEN (SELECT * FROM table2 WHERE ...)
END;
I am new to SQL. What construct would be the most concise (not ugly) solution and if I cannot have it in sqlite, what RDBM would be the best fit?
Thanks
Here is a proposal for associating a value from one of two tables for each entry in mytable. I.e. this is making the assumption that mytable does not only contain a single entry for choosing the secondary table.
For details on what this means, see "MCVE" at the end of this answer.
If you want to switch between two secondary tables, based on a single entry in main table, see at the very end of this answer.
Details:
a hardcoded "value1"/"value2" as column1 added on the fly to the result from secondary tables
joining by the faked colummn1 and a secondary join-key, assumption here id
a union all to make a single table from both secondary tables (including the fake column1)
select *
from mytable
left join
(select 'value1' as column1, * from table1
UNION ALL
select 'value2' as column1, * from table2)
using(id, column1);
Output (for the MCVE provided below, "a-f" from table1, "A-Z" from table2):
value1|1|a
value2|2|B
value1|3|c
value1|4|d
value2|5|E
value2|6|F
MCVE:
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE mytable (column1 varchar(10), id int);
INSERT INTO mytable VALUES('value1',1);
INSERT INTO mytable VALUES('value2',2);
INSERT INTO mytable VALUES('value1',3);
INSERT INTO mytable VALUES('value1',4);
INSERT INTO mytable VALUES('value2',5);
INSERT INTO mytable VALUES('value2',6);
CREATE TABLE table2 (value varchar(2), id int);
INSERT INTO table2 VALUES('F',6);
INSERT INTO table2 VALUES('E',5);
INSERT INTO table2 VALUES('D',4);
INSERT INTO table2 VALUES('C',3);
INSERT INTO table2 VALUES('B',2);
INSERT INTO table2 VALUES('A',1);
CREATE TABLE table1 (value varchar(2), id int);
INSERT INTO table1 VALUES('a',1);
INSERT INTO table1 VALUES('b',2);
INSERT INTO table1 VALUES('c',3);
INSERT INTO table1 VALUES('d',4);
INSERT INTO table1 VALUES('e',5);
INSERT INTO table1 VALUES('f',6);
COMMIT;
For selecting between two tables based on a single entry in main table (in this case "mytable2":
select * from table1 where (select column1 from mytable2) = 'value1'
union all
select * from table2 where (select column1 from mytable2) = 'value2';
Output (with mytable2 only containing 'value1'):
a|1
b|2
c|3
d|4
e|5
f|6
I know we could use
Insert Into table_name(cloumn_names)
Select column_names
From table_name
but how about Select Into? Can we also use Select Into to copy data from one table to another EXISTING table using? I mean can we specify the column names of the latter table using Select Into?
Thx!
You can use insert into select syntax
INSERT INTO table2 (column1, column2, column3, ...)
SELECT column1, column2, column3, ...
FROM table1
WHERE condition;
It basically selects columns from table1 and respectively insert in table 2
SELECT INTO
This method is used when table is not created earlier and needs to be created when data from one table is to be inserted into newly created table from another table. New table is created with same data types as selected columns.
Inserting Rows by Using SELECT INTO
You can try this :
UPDATE [TestDB].[dbo].[Table1]
SET [Content] = (
Select [TestDB].[dbo].[Table2].[Content] from Table2 where ID= 'XYZ')
WHERE [ID] = 'XYZ'
GO
How to copy/append data from one table into another table with same schema in SQL Server?
Edit:
let's say there is a query
select *
into table1
from table2
where 1=1
which creates table1 with the same schema as well as data as in table2.
Is there any short query like this to only copy entire data only into an already existing table?
If both tables are truly the same schema:
INSERT INTO newTable
SELECT * FROM oldTable
Otherwise, you'll have to specify the column names (the column list for newTable is optional if you are specifying a value for all columns and selecting columns in the same order as newTable's schema):
INSERT INTO newTable (col1, col2, col3)
SELECT column1, column2, column3
FROM oldTable
Simple way if new table does not exist and you want to make a copy of old table with everything then following works in SQL Server.
SELECT * INTO NewTable FROM OldTable
This is the proper way to do it:
INSERT INTO destinationTable
SELECT * FROM sourceTable
INSERT INTO table1 (col1, col2, col3)
SELECT column1, column2, column3
FROM table2
Try this:
INSERT INTO MyTable1 (Col1, Col2, Col4)
SELECT Col1, Col2, Col3 FROM MyTable2
Try this:
Insert Into table2
Select * from table1
Insert Selected column with condition
INSERT INTO where_to_insert (col_1,col_2) SELECT col1, col2 FROM from_table WHERE condition;
Copy all data from one table to another with the same column name.
INSERT INTO where_to_insert
SELECT * FROM from_table WHERE condition;
INSERT INTO DestinationTable(SupplierName, Country)
SELECT SupplierName, Country FROM SourceTable;
It is not mandatory column names to be same.
CREATE TABLE `table2` LIKE `table1`;
INSERT INTO `table2` SELECT * FROM `table1`;
the first query will create the structure from table1 to table2 and second query will put the data from table1 to table2
Copy all columns from one table to another table:
INSERT INTO table2
SELECT * FROM table1
WHERE condition;
Copy only some columns from one table into another table:
INSERT INTO table2 (column1, column2, column3, ...)
SELECT column1, column2, column3, ...
FROM table1
WHERE condition;
You can duplicate or "clone" a table's contents by executing:
CREATE TABLE new_table AS SELECT * FROM original_table;
-- for Sql Server users.
if you don't have the new table then you can create the new table with same structure as old table, and also copy data over from old table to the new table. For example:
select * into new_table
from old_table;
also you can copy the column / table structure, and just some of data. For example:
select * into new_table
from old_table
where country = 'DE';
I wanted to select the last record from the table1 and insert into another table .Here is my query.
Insert into table2 values(select top 1 col1,col2 from table1 order by id desc).
I know for adding the value into table,need to be in cotation.But where to add?
You can select literals to fill in the other columns that table1 can't provide, something like this:
insert into table2 (col_a, col_b, col_c, col_d)
select top 1 col1, col2, 'foo', 'bar'
from table1
order by id desc
Any columns you do not name in the column list will get the default value, or null if no default is defined.
The number and type of columns selected must match the number and type of columns in the insert column list.
In SQL, there are essentially basically two ways to INSERT data into a table: One is to insert it one row at a time, the other is to insert multiple rows at a time. Let's take a look at each of them individually:
INSERT INTO table_name (column1, column2, ...)
VALUES ('value1', 'value2', ...)
The second type of INSERT INTO allows us to insert multiple rows into a table. Unlike the previous example, where we insert a single row by specifying its values for all columns, we now use a SELECT statement to specify the data that we want to insert into the table. If you are thinking whether this means that you are using information from another table, you are correct. The syntax is as follows:
INSERT INTO table1 (column1, column2, ...)
SELECT t2.column3, t2.column4, ...
FROM table2 t2
So, in you case, you can do it like this:
Insert into table2
select top 1 t1.col1,t1.col2 from table1 t1 order by id desc
Or you can use your syntax like this:
declare #col1 type_of_col1, #col2 type_of_col2
select top 1 #col1 = t1.col1, #col2 = t1.col2 from table1 t1 order by id desc
Insert into table2 values(#col1, #col2)
Offcourse, this all works assuming that the column datatypes are matched.
I have two identical tables and need to copy rows from table to another. What is the best way to do that? (I need to programmatically copy just a few rows, I don't need to use the bulk copy utility).
As long as there are no identity columns you can just
INSERT INTO TableNew
SELECT * FROM TableOld
WHERE [Conditions]
Alternative syntax:
INSERT tbl (Col1, Col2, ..., ColN)
SELECT Col1, Col2, ..., ColN
FROM Tbl2
WHERE ...
The select query can (of course) include expressions, case statements, constants/literals, etc.
Jarrett's answer creates a new table.
Scott's answer inserts into an existing table with the same structure.
You can also insert into a table with different structure:
INSERT Table2
(columnX, columnY)
SELECT column1, column2 FROM Table1
WHERE [Conditions]
SELECT * INTO < new_table > FROM < existing_table > WHERE < clause >
INSERT INTO DestTable
SELECT * FROM SourceTable
WHERE ...
works in SQL Server
To select only few rows..This will work like charm..
SELECT TOP 10 *
INTO db2.dbo.new_table
FROM db1.dbo.old_table;
Note : Just create a new table in the required db..We need not define its structure.