# Sequences already exists error

**URL:** <https://forum.liquibase.org/t/sequences-already-exists-error/2481>\
**Category:** Liquibase Development\
**Created:** [July 11, 2011, 4:30pm UTC](https://forum.liquibase.org/t/sequences-already-exists-error/2481 "2011-07-11T16:30:00Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Guest](https://avatars.discourse-cdn.com/v4/letter/g/8dc957/32.png) [@Guest](https://forum.liquibase.org/u/Guest)\
**Post date:** [July 11, 2011, 4:30pm UTC](https://forum.liquibase.org/t/sequences-already-exists-error/2481/1 "2011-07-11T16:30:00Z")

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Hi,  
  
  
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when this changeSet executed , the implicit sequence was generated on the table message\_sent column bssentmsgid.  
  
  
After generate changeLog performed ,all tables,indexes,constraints and sequences will be generarted in a single xml file.afte that if i execute lb\_install.bat on empty schema,sequence already exists errot coming. i am trying to drop the implicit sequence ,but it’s giving error like can’t drop implicit sequences,drop table is recommended.if i drop the table i lost it’s content.  
  
  
So.how to resolve this problem?  
i am using postgresql data base.  
  
  
  
please help anyone,thanks in Advance…