If you define the columns with double quotes, then you generally need to use them when you refer to the column: insert into tester3 (“UN0”, “UN1”) values ( 1, ‘jishnu1′); I would suggest you remove the double quotes from the column names in the CREATE TABLE statement. You don’t need the double quotes if the … Read more
Usually one would simply truncate the datetime with TRUNC: TRUNC(pa.fromdate) This removes the time part from the datetime, so you get the mere date. Then in your application layer, you would care about how to display it. For example you have a GUI with a grid. The grid displays the dates according to the user’s … Read more
Generally, there is no downside to using text in terms of performance/memory. On the contrary: text is the optimum. Other types have more or less relevant downsides. text is literally the “preferred” type among string types in the Postgres type system, which can affect function or operator type resolution. In particular, never use char(n) (alias … Read more
SELECT MIN(date_col), MAX(date_col) FROM table_name
Using the psql(1) interactive terminal There is another way, at least in recent Postgres versions. Use the \ddp command Default access privileges Owner | Schema | Type | Access privileges —————-+——–+———-+——————- role_x | | function | =X/role_x role_x | | sequence | role_x | | table | role_x | | type | =U/role_x Read more … Read more
In PostgreSQL 9.x, you can grant permissions on all sequences in one schema to a role. The syntax is GRANT SELECT ON ALL SEQUENCES IN SCHEMA schema_name TO role_name The role can be either a group role or a login role (user name).
As for now, this is not possible. Here is the documentation on what may be used in the FROM clause: table_references: table_reference [, table_reference] … table_reference: table_factor | join_table table_factor: tbl_name [[AS] alias] [index_hint)] | table_subquery [AS] alias | ( table_references ) | { OJ table_reference LEFT OUTER JOIN table_reference ON conditional_expr } join_table: table_reference … Read more
You’ve got it correct. In a “SELECT FOR UPDATE” with a JOIN, any rows that contribute to the returned rows will be locked. You can change this behavior by adding an “OF table_a” to the “FOR UPDATE” so that only the rows from table_a will be locked. You can read more about this in the … Read more
In the end, I settled for the following : Drop: df.drop(‘column_1’, ‘column_2’, ‘column_3’) Select : df.select([c for c in df.columns if c not in {‘column_1’, ‘column_2’, ‘column_3’}])
You need to define a cast to be used because there is no default cast available. If all values in the varcharColumn comply with the enum definition, the following should work: alter table foo ALTER COLUMN varcharColumn TYPE enum_type using varcharColumn::enum_type; I personally don’t like enums because they are quite unflexible. I prefer a check … Read more