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Create a table without a header in Markdown
Is it possible to create a table without a header in Markdown?
11 Answers
11
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How to change collation of database, table, column?
...
You need to either convert each table individually:
ALTER TABLE mytable CONVERT TO CHARACTER SET utf8mb4
(this will convert the columns just as well), or export the database with latin1 and import it back with utf8mb4.
...
How do I get a list of column names from a psycopg2 cursor?
... If you just want the column names, don't select all of the rows in the table. This is more efficient: curs.execute("SELECT * FROM people LIMIT 0")
– Demitri
Sep 6 '12 at 22:03
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Only read selected columns
...hs (7 columns) for each year of the data below, for example by using read.table() ?
4 Answers
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SQLAlchemy: print the actual query
...'literal_binds' flag, passed to compile_kwargs:
from sqlalchemy.sql import table, column, select
t = table('t', column('x'))
s = select([t]).where(t.c.x == 5)
print(s.compile(compile_kwargs={"literal_binds": True}))
the above approach has the caveats that it is only supported for basic
types, su...
Best practices for in-app database migration for Sqlite
...anges aren't committed.
For making schema changes, sqlite supports "ALTER TABLE" syntax for certain operations (renaming the table or adding a column). This is an easy way to update existing tables in-place. See the documentation here: http://www.sqlite.org/lang_altertable.html. For deleting col...
List all sequences in a Postgres db 8.1 with SQL
...ROM pg_class c WHERE c.relkind = 'S';
Typically a sequence is named as ${table}_id_seq. Simple regex pattern matching will give you the table name.
To get last value of a sequence use the following query:
SELECT last_value FROM test_id_seq;
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Bulk insert with SQLAlchemy ORM
...scoped_session(sessionmaker())
engine = None
class Customer(Base):
__tablename__ = "customer"
id = Column(Integer, primary_key=True)
name = Column(String(255))
def init_sqlalchemy(dbname='sqlite:///sqlalchemy.db'):
global engine
engine = create_engine(dbname, echo=False)
...
Rails :include vs. :joins
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.joins will just joins the tables and brings selected fields in return. if you call associations on joins query result, it will fire database queries again
:includes will eager load the included associations and add them in memory. :includes loads all...
Efficiently convert rows to columns in sql server
...Code, LastName, AccountNumber
from
(
select value, columnname
from yourtable
) d
pivot
(
max(value)
for columnname in (Firstname, Amount, PostalCode, LastName, AccountNumber)
) piv;
See Demo.
Pivot with unknown number of columnnames
If you have an unknown number of columnnames that you w...