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python-pandas and databases like mysql
...a_conn = cx_Oracle.connect('your_connection_string')
df_ora = pd.read_sql('select * from user_objects', con=ora_conn)
print 'loaded dataframe from Oracle. # Records: ', len(df_ora)
ora_conn.close()
And here is the equivalent example for MySQLdb:
import MySQLdb
mysql_cn= MySQLdb.connect(host='...
Maximum number of characters using keystrokes A, Ctrl+A, Ctrl+C and Ctrl+V
...rate through for i up to n, doing two things: pressing A once and pressing select all + copy followed by paste j times (actually j-i-1 below; note the trick here: the contents are still in the clipboard, so we can paste it multiple times without copying each time). We only have to consider up to 4 c...
How to remove all MySQL tables from the command-line without DROP database permissions? [duplicate]
...tatements to execute it:
SET FOREIGN_KEY_CHECKS = 0;
SET @tables = NULL;
SELECT GROUP_CONCAT('`', table_schema, '`.`', table_name, '`') INTO @tables
FROM information_schema.tables
WHERE table_schema = 'database_name'; -- specify DB name here.
SET @tables = CONCAT('DROP TABLE ', @tables);
PRE...
How do I check if a SQL Server text column is empty?
...
Actually, you just have to use the LIKE operator.
SELECT * FROM mytable WHERE mytextfield LIKE ''
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Selecting/excluding sets of columns in pandas [duplicate]
...e to create views or dataframes from an existing dataframe based on column selections.
9 Answers
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psql - save results of command to a file
...peruser privileges and will write to a file on the server.
Example: COPY (SELECT foo, bar FROM baz) TO '/tmp/query.csv' (format csv, delimiter ';')
Creates a CSV file with ';' as the field separator.
As always, see the documentation for details
...
Select parent element of known element in Selenium
I have a certain element that I can select with Selenium 1.
7 Answers
7
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How to change column order in a table using sql query in sql server 2005?
... to look at the data in a table with a given column order when you make a "SELECT *". I'm a developer and do this kind of queries all the time. You can spare some time with a good pre-defined column order. From any other standpoint, of course, it has no sense: nothing should depend on the column ord...
How do I see all foreign keys to a table or column?
...
For a Table:
SELECT
TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME, REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME
FROM
INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE
REFERENCED_TABLE_SCHEMA = '<database>' AND
REFERENCED_TABLE_NAME = '<...
How to get the next auto-increment id in mysql
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You can use
SELECT AUTO_INCREMENT
FROM information_schema.tables
WHERE table_name = 'table_name'
AND table_schema = DATABASE( ) ;
or if you do not wish to use information_schema you can use this
SHOW TABLE STATUS LIKE 'table_name'
...