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MySQL: Insert record if not exists in table
...oDB;
Insert a record:
INSERT INTO table_listnames (name, address, tele)
SELECT * FROM (SELECT 'Rupert', 'Somewhere', '022') AS tmp
WHERE NOT EXISTS (
SELECT name FROM table_listnames WHERE name = 'Rupert'
) LIMIT 1;
Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
...
How to discard local commits in Git?
... worked. Discarded all local commits and reset to HEAD. Whats the use of ^ char?
– karim
Nov 22 '19 at 13:58
@karim th...
What is the reason not to use select *?
...eople claim that you should specifically name each column you want in your select query.
20 Answers
...
is it possible to select EXISTS directly as a bit?
...workaround.
If you must return a conditional bit 0/1 another way is to:
SELECT CAST(
CASE WHEN EXISTS(SELECT * FROM theTable where theColumn like 'theValue%') THEN 1
ELSE 0
END
AS BIT)
Or without the cast:
SELECT
CASE
WHEN EXISTS( SELECT 1 FROM theTable WHERE theColumn LI...
Difference between Select Unique and Select Distinct
...
SELECT UNIQUE is old syntax supported by Oracle's flavor of SQL. It is synonymous with SELECT DISTINCT.
Use SELECT DISTINCT because this is standard SQL, and SELECT UNIQUE is non-standard, and in database brands other than ...
Getting the minimum of two values in SQL
...led OwedPast . They are both results of some subqueries in SQL. How can I select the smaller of the two and return it as a value titled PaidForPast ?
...
How to select option in drop down protractorjs e2e tests
I am trying to select an option from a drop down for the angular e2e tests using protractor.
31 Answers
...
How can I read large text files in Python, line by line, without loading it into memory?
...in sensible sized chunks (kilobytes to megabytes say) and split on newline characters ( or whatever the line ending char is on your platform)
– John La Rooy
Jun 25 '11 at 2:36
4
...
SQL Server : Columns to Rows
...
You can use the UNPIVOT function to convert the columns into rows:
select id, entityId,
indicatorname,
indicatorvalue
from yourtable
unpivot
(
indicatorvalue
for indicatorname in (Indicator1, Indicator2, Indicator3)
) unpiv;
Note, the datatypes of the columns you are unpivoting mus...
How do I remove an item from a stl vector with a certain value?
..., my visual studio takes std::remove with only one argument; that is const char *_Filename. What method do I need to call?
– Victor
Aug 24 '13 at 12:28
15
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