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What is the difference between JOIN and UNION?
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Joins and Unions can be used to combine data from one or more tables. The difference lies in how the data is combined.
In simple terms, joins combine data into new columns. If two tables are joined together, then the data from the first table is shown in one set of column alongside t...
How to change identity column values programmatically?
I have a MS SQL 2005 database with a table Test with column ID . ID is an identity column.
13 Answers
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Which are more performant, CTE or temporary tables?
Which are more performant, CTE or Temporary Tables ?
12 Answers
12
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Passing Data between View Controllers
...igationController pushViewController:vc animated:NO];
fire block
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:
(NSIndexPath *)indexPath {
NSString *voucher = vouchersArray[indexPath.row];
if (sourceVC.selectVoucherBlock) {
sourceVC.selectVoucherBlock(voucher)...
CSS3's border-radius property and border-collapse:collapse don't mix. How can I use border-radius to
...-collapse:collapse in CSS (in order to have a collapsed, rounded corner table)?
24 Answers
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MVC (Laravel) where to add logic
...E.g., whenever someone publishes a post I also want to save something to a table for analytics. Maybe not the best example but in general there's a lot of this "grouped" functionality.
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How do I add more members to my ENUM-type column in MySQL?
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ALTER TABLE
`table_name`
MODIFY COLUMN
`column_name2` enum(
'existing_value1',
'existing_value2',
'new_value1',
'new_value2'
)
NOT NULL AFTER `column_name1`;
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Query to count the number of tables I have in MySQL
I am growing the number of tables I have and I am sometimes curious just to do a quick command line query to count the number of tables in my database. Is that possible? If so, what is the query?
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Find all tables containing column with specified name - MS SQL Server
Is it possible to query for table names which contain columns being
29 Answers
29
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Mysql error 1452 - Cannot add or update a child row: a foreign key constraint fails
... having a bit of a strange problem. I'm trying to add a foreign key to one table that references another, but it is failing for some reason. With my limited knowledge of MySQL, the only thing that could possibly be suspect is that there is a foreign key on a different table referencing the one I am ...