jackie-do/[postgresql]_update_auto_increment_field_manually.md

## [postgresql]_update_auto_increment_field_manually.md

      
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              [postgresql]_update_auto_increment_field_manually.md
            
          
Get the max current value of a field (base on current data)

SELECT MAX(<field_name>) FROM <table_name>;

example:
SELECT MAX(id) FROM blogs;


Get the current value of an auto-increment field (for checking)

SELECT currval(pg_get_serial_sequence('<table_name>', '<field_name>'));
# or
SELECT currval('<table_name_field_name_seq>');

example:
SELECT currval(pg_get_serial_sequence('blogs', 'id'));
# or
SELECT currval('blogs_id_seq');


Get the next value of an auto-increment field (for checking)

SELECT nextval(pg_get_serial_sequence('<table_name>', '<field_name>'));
# or
SELECT nextval('<table_name_field_name_seq>');

example:
SELECT nextval(pg_get_serial_sequence('blogs', 'id'));
# or
SELECT nextval('blogs_id_seq');


Update the value of auto-increment field manually

SELECT setval(pg_get_serial_sequence('<table_name>', '<field_name>'), <value>);
# or
SELECT setval('<table_name_field_name_seq>', <value>);

example:
SELECT setval('blogs_id_seq', (SELECT MAX(id) FROM blogs) + 1 );