I have 700 tables in a test.db file, and was wondering how do I loop through all these tables and return the table name if columnA value is -?
connection.execute('SELECT * FROM "all_tables" WHERE "columnA" = "-"')
How do I put all 700 tables in all_tables?
To continue on a theme:
import sqlite3
try:
conn = sqlite3.connect('/home/rolf/my.db')
except sqlite3.Error as e:
print('Db Not found', str(e))
db_list = []
mycursor = conn.cursor()
for db_name in mycursor.execute("SELECT name FROM sqlite_master WHERE type = 'table'"):
db_list.append(db_name)
for x in db_list:
print "Searching",x[0]
try:
mycursor.execute('SELECT * FROM '+x[0]+' WHERE columnA" = "-"')
stats = mycursor.fetchall()
for stat in stats:
print stat, "found in ", x
except sqlite3.Error as e:
continue
conn.close()
SQLite
get all tables name:
SELECT name FROM sqlite_master WHERE type='table' ORDER BY name;
Cycle
for table in tables:
...
connection.execute('SELECT * FROM "table1" WHERE "columnA" = "-"')
or one SQL request UNION
sql = []
for table in tables
sql.append('(SELECT * FROM "' + table + '" WHERE "columnA" = "-";)')
' UNION '.join(sql)
You could query the sqlite_master to get all the table names within your database: SELECT name FROM sqlite_master WHERE type = 'table'
sqlite_master can be thought of as a table that contains information about your databases (metadata).
A quick but most likely inefficient way (because it will be running 700 queries with 700 separate resultsets) to get the list of table names, loop through those tables and return data where columnA = "-":
for row in connection.execute('SELECT name FROM sqlite_master WHERE type = "table" ORDER BY name').fetchall()
for result in connection.execute('SELECT * FROM ' + row[1] + ' WHERE "columnA" = "-"').fetchall()
# do something with results
Note: Above code is untested but gives you an idea on how to approach this.
