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Get table column names in MySQL?
...DESCRIBE my_table;
Or in newer versions you can use INFORMATION_SCHEMA:
SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'my_database' AND TABLE_NAME = 'my_table';
Or you can use SHOW COLUMNS:
SHOW COLUMNS FROM my_table;
...
How can I return two values from a function in Python?
...s, but you can return a tuple or a list and unpack it after the call:
def select_choice():
...
return i, card # or [i, card]
my_i, my_card = select_choice()
On line return i, card i, card means creating a tuple. You can also use parenthesis like return (i, card), but tuples are created ...
MySQL Query GROUP BY day / month / year
... for added clarity in some cases such as where records span several years. SELECT COUNT(event_id), DATE_FORMAT(event_start, '%Y/%m')
– Ric
Apr 4 '13 at 10:25
...
MySQL - Get row number on select
Can I run a select statement and get the row number if the items are sorted?
5 Answers
...
How can I get the list of a columns in a table for a SQLite database?
...(first_name varchar, last_name varchar, email_address varchar);
sqlite> select * from sqlite_master;
table|people|people|2|CREATE TABLE people (first_name varchar, last_name varchar, email_address varchar)
To get column information you can use the pragma table_info(table_name) statement:
sqlit...
Selecting a row of pandas series/dataframe by integer index
...
The primary purpose of the DataFrame indexing operator, [] is to select columns.
When the indexing operator is passed a string or integer, it attempts to find a column with that particular name and return it as a Series.
So, in the question above: df[2] searches for a column name matchin...
SQL to find the number of distinct values in a column
I can select all the distinct values in a column in the following ways:
11 Answers
11
...
SQL update fields of one table from fields of another one
...ic SQL is totally non-standard PostgreSQL syntax.
DO
$do$
BEGIN
EXECUTE (
SELECT
'UPDATE b
SET (' || string_agg( quote_ident(column_name), ',') || ')
= (' || string_agg('a.' || quote_ident(column_name), ',') || ')
FROM a
WHERE b.id = 123
AND a.id = b.id'
FROM i...
Mysql order by specific ID values
... use ORDER BY and FIELD function.
See http://lists.mysql.com/mysql/209784
SELECT * FROM table ORDER BY FIELD(ID,1,5,4,3)
It uses Field() function, Which "Returns the index (position) of str in the str1, str2, str3, ... list. Returns 0 if str is not found" according to the documentation. So actual...
How to get ID of the last updated row in MySQL?
...)
SET @update_id := 0;
UPDATE some_table SET column_name = 'value', id = (SELECT @update_id := id)
WHERE some_other_column = 'blah' LIMIT 1;
SELECT @update_id;
EDIT by aefxx
This technique can be further expanded to retrieve the ID of every row affected by an update statement:
SET @uids := nul...