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How do I get SUM function in MySQL to return '0' if no values are found?
...Use COALESCE to avoid that outcome.
SELECT COALESCE(SUM(column),0)
FROM table
WHERE ...
To see it in action, please see this sql fiddle: http://www.sqlfiddle.com/#!2/d1542/3/0
More Information:
Given three tables (one with all numbers, one with all nulls, and one with a mixture):
SQL Fidd...
How do you join on the same table, twice, in mysql?
I have 2 tables. One (domains) has domain ids, and domain names (dom_id, dom_url).
3 Answers
...
T-SQL query to show table definition?
...l show me the full definition, including indexes and keys for a SQL Server table? I want a pure query - and know that SQL Studio can give this to me, but I am often on "wild" computers that have only the most bare-bones apps and I have no rights to install studio. But SQLCMD is always an option.
...
Are table names in MySQL case sensitive?
Are table names in MySQL case sensitive?
5 Answers
5
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When should I use a table variable vs temporary table in sql server?
I'm learning more details in table variable. It says that temp tables are always on disk, and table variables are in memory, that is to say, the performance of table variable is better than temp table because table variable uses less IO operations than temp table.
...
How can I search for a multiline pattern in a file?
...l regex by adding -P. find . -exec grep -nHP '(?s)SELECT.{1,60}FROM.{1,20}table_name' '{}' \;
– Jim
Feb 22 '13 at 13:02
...
How do I integrate Ajax with Django applications?
...lly, with ajax it is failing. With ajax, I am able to save only the header table data. But when I am trying to save child table data also, it is failing with error 400 (Bad request). Tried PDB but could not resolve it.
– shaan
Jul 15 at 6:28
...
How to append rows to an R data frame
...O I come with 4 distinct solutions:
rbindlist to the data.frame
Use data.table's fast set operation and couple it with manually doubling the table when needed.
Use RSQLite and append to the table held in memory.
data.frame's own ability to grow and use custom environment (which has reference seman...
How do I select an entire row which has the largest ID in the table?
...
You could use a subselect:
SELECT row
FROM table
WHERE id=(
SELECT max(id) FROM table
)
Note that if the value of max(id) is not unique, multiple rows are returned.
If you only want one such row, use @MichaelMior's answer,
SELECT row from table ORDER BY ...
How to fix “Incorrect string value” errors?
...ecting:
SET NAMES 'utf8';
SET CHARACTER SET utf8;
Next, verify that the tables where the data is stored have the utf8 character set:
SELECT
`tables`.`TABLE_NAME`,
`collations`.`character_set_name`
FROM
`information_schema`.`TABLES` AS `tables`,
`information_schema`.`COLLATION_CHARACTER_S...