in mysql i can create a table named "select" using the following statement
CREATE TABLE `SELECT` (
Id INT,
Name VARCHAR(255)
}
and it executed successfully and the table is created by the name "select" as you can see the image above. But the same couldn't be done in oracle 11g.
What would be the sql query that's required to create a table named "select" in other sql databases
I think you should use
CREATE TABLE "SELECT" ...
use dumme
create table [select]
(
i int
)
select * from [select]
i dont know why you in such need to create table with reserve word but in MS SQL server 2005 you can use the above statment to create a table with name select
Select is a reserved word, and tgus should actually not be used. The validation in mysql is just a little less strict.
Try using another name, like selectTable or selectId
Related
how we can check if a column exists on Table in MySQL without using Stored Procedure. MySQL v3.23 which won't support writing Store Procedure.
v3.23 ?? If You know the table name and column name then try describe tablename or show create tablename if you know only column name select * from information schema.columns where column_name = columnname. Show tables should show all tables then manually select column name from the listed tables.
But this version is so ancient I have no idea if any of these will work
Try this, counting the columns in your table using the information_schema.COLUMNS.
SELECT COUNT(*) FROM information_schema.`COLUMNS`
WHERE table_schema = 'your_database_name'
AND table_name='your_table_name'
AND column_name='your_column_name';
The INFORMATION_SCHEMA COLUMNS Tabletable provides information about columns in tables.
Link
Is it necessary to define the new table definition before using SELECT INTO query in MYSQL.
I am getting problem to execute the query when I writ e like:
SELECT *
INTO newtable
FROM oldtable
WHERE 1=0;
the error showing is:
Undeclared variabie: newtable
if you have newtable
try :
INSERT INTO newtable SELECT ...
if you don't have newtable
try :
CREATE TABLE newtable AS SELECT ...
The MySQL manual search engine is terrible but googling for something like mysql 5.5 select into will normally take you to the right page:
MySQL Server doesn't support the SELECT ... INTO TABLE Sybase SQL
extension. Instead, MySQL Server supports the INSERT INTO ... SELECT
standard SQL syntax, which is basically the same thing.
If you read the documentation here it says:
With INSERT ... SELECT, you can quickly insert many rows into a table from one or many tables
So, yes, you need to create the new table first.
You can use CREATE TABLE new LIKE old to create a new, empty table, which is a copy of the original table structure.
I run this query
CREATE TEMPORARY TABLE usercount SELECT * FROM users
I get this message
Your SQL query has been executed successfully ( Query took 0.1471 sec )
But when I try to access the newly created table using
SELECT * FROM usercount
I get this error
#1146 - Table 'abc_site.usercount' doesn't exist
Not sure why, I need to mention that I've did a good share of googling beforehand.
My version of PHPMyAdmin is 3.5.2.2 and MySQL 5.5.27
PHPMyAdmin (or rather PHP) closes the database connection after each screen. Thus your temporary tables disappear.
You can put multiple SQL statements in the SQL query box in PHPMyAdmin; this should be executed as one block and thus the temporary table is not deleted.
Temporary tables are temparar and after use thay Delete.
for example ,when insert data into database , first we can insert into temp table and thus when complete transaction , then insert into main table.
EXAMPLE :
//------------------------------------------
CREATE TEMPORARY TABLE TEMP
(
USERNAME VARCHAR(50) NOT NULL,
PASSWORD VARCHAR(50) NOT NULL,
EMAIL varchar(100),
TYPE_USER INT
);
INSERT INTO TEMP VALUES('A','A','A','1');
SELECT * FROM TEMP
//-----------------------------------------
Show A,A,A,1
I would like to get count of specific records. So my query will look like the following...
SELECT
ID,
NAME,
(SELECT...) AS UserCount // Stmt1
FROM MyTable
The issue is that, 'Stmt1' is a complex statement and it cannot be written as innerquery.
Well, I can use functions, but the statement includes 'CREATE TABLE' so I get the following error message
Cannot access temporary tables from within a function.
What is the best way to accomplish the task ?
You can use user defined table type to solve your problem.
You just create a table variable like
CREATE TYPE [dbo].[yourTypeName] AS TABLE(
[columeName1] [int] NULL,
[columeName2] [varchar](500) NULL,
[columeName3] [varchar](1000) NULL
)
GO
and you can declare this table variable in your function like
CREATE FUNCTION [dbo].[yourFunctionName]
(
#fnVariable1 INT ,
#yourTypeNameVariable yourTypeName READONLY
)
RETURNS VARCHAR(8000)
AS
BEGIN
SELECT .................
FROM #yourTypeNameVariable
WHERE ........
RETURN #r
END
On your procedure you can declare your table type like
DECLARE #yourTypeNamevaribale AS yourTypeName
And you can insert values to this table like
insert into #yourTypeNamevaribale (col,col,..)values(val,val,..)
pass this to your function like
dbo.yourFunctionName(fnVariable1 ,#yourTypeNamevaribale )
please go for this method, thank you
Yes you can not use #temp table.
As you are using SQL Server 2008, why don't you use table variable instead of #temp tables?
Give it a try.
I came across this post as I started using table variables and switched to temporary tables for performance reasons only to find temporary tables couldn't be used in a function.
I would be hesitant about using table variables especially if you are playing with large result sets, as these are held in memory. See this post...
http://totogamboa.com/2010/12/03/speed-matters-subquery-vs-table-variable-vs-temporary-table/
Other alternatives would be..
Extracting the temporary table result into another table function.
Converting the code into using sub-queries
In 99,99% of cases there is no need for any tricks with temp tables or subqueries, but use aggregation functions like COUNT, SUM or AVG in combination with OVER clause and (often) PARTITION BY.
I am not sure what the OP tried to achieve but I assume that the UserCount is somehow related to the values in MyTable. So there must be a way to join MyTable to whatever table that produces UserCount.
The most simple example is to show all users and the total number of users
SELECT id
, name
, user_count = COUNT(*) OVER()
FROM MyUsers
I've recently moved from MSSQL to MySQL.
I would like to use a table variable (or equivalent) inside a MySQL 5.5 stored routine, to populate a dataset for an online report.
In MS SQL, I would do it this way
...
...
DECLARE #tblName TABLE
WHILE <condition>
BEGIN
Insert Row based on iteration value
END
...
...
From what I understand, I can't declare table variables in MySQL (correct me if I'm wrong) How do I implement the above logic in a MySQL stored procedure?
You could create a table or temporary table and populate it with data you need.
CREATE TABLE Syntax
You understand that limitation correctly. The MySQL user manual clearly states that user-defined variables cannot refer to a table:
http://dev.mysql.com/doc/refman/5.5/en/user-variables.html
User variables are intended to provide data values. They cannot be used directly in an SQL statement as an identifier or as part of an identifier, such as in contexts where a table or database name is expected, or as a reserved word such as SELECT.
create temporary table tmp
(
id int unsigned not null,
name varchar(32) not null
)
engine=memory; -- change engine type if required e.g myisam/innodb
insert into tmp (id, name) select id, name from foo... ;
-- do more work...
select * from tmp order by id;
drop temporary table if exists tmp;
I think this covers it. Also, this may be helpful.