Top 14 Python Libraries for Data Science and Machine Learning
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1. To convert an existing integer column to auto-increment type 'serial' :
# Create a sequence called TABLE_id_seq (replace TABLE with actual table name). Find the maximum number and start the sequence with the next number. For example say max(id) is 30, then start with 31.
Command: create sequence TABLE_id_seq start with 31;
Anytime you can restart the sequence with 'restart with' option.
#Alter the table's column with default nextval function which will increment the integer when new rows are inserted into the table.
Command: alter table TABLE alter column COLUMN set default nextval('TABLE_id_seq');
2. To copy a table to a new one use commands:
create table NewTable as select * from OldTable;
alter table OldTable rename to Newname;
3. To rename a column:
alter table Table rename column Column to Newname