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Insert into … values ( SELECT … FROM … )
I am trying to INSERT INTO a table using the input from another table. Although this is entirely feasible for many database engines, I always seem to struggle to remember the correct syntax for the SQL engine of the day ( MySQL , Oracle , SQL Server , Informix , and DB2 ).
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Colspan all columns
... td tag should span all columns (when the exact amount of columns in the table will be variable/difficult to determine when the HTML is being rendered)? w3schools mentions you can use colspan="0" , but it doesn't say exactly what browsers support that value (IE 6 is in our list to support).
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Query to list number of records in each table in a database
How to list row count of each table in the database. Some equivalent of
21 Answers
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Force drop mysql bypassing foreign key constraint
I'm trying to delete all tables from a database except one, and I end up having the following error:
6 Answers
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Select random row from a sqlite table
I have a sqlite table with the following schema:
7 Answers
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PostgreSQL create table if not exists
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This feature has been implemented in Postgres 9.1:
CREATE TABLE IF NOT EXISTS myschema.mytable (i integer);
For older versions, here is a function to work around it:
CREATE OR REPLACE FUNCTION create_mytable()
RETURNS void
LANGUAGE plpgsql AS
$func$
BEGIN
IF EXISTS (SELECT...
CROSS JOIN vs INNER JOIN in SQL
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Cross join does not combine the rows, if you have 100 rows in each table with 1 to 1 match, you get 10.000 results, Innerjoin will only return 100 rows in the same situation.
These 2 examples will return the same result:
Cross join
select * from table1 cross join table2 where table1.id = ...
Tools for making latex tables in R [closed]
On general request, a community wiki on producing latex tables in R. In this post I'll give an overview of the most commonly used packages and blogs with code for producing latex tables from less straight-forward objects. Please feel free to add any I missed, and/or give tips, hints and little trick...
What is a 'multi-part identifier' and why can't it be bound?
I continually get these errors when I try to update tables based on another table. I end up rewriting the query, change the order of joins, change some groupings and then it eventually works, but I just don't quite get it.
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How to design a product table for many kinds of product where each product has many parameters
I do not have much experience in table design. My goal is to create one or more product tables that meet the requirements below:
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