SQL truncate length of a string

Question

我在postgreSQL中有一个表程序员（id，name），我想返回所有程序员的名字，如果一个名字超过12个字符，我想把它截断为12个字符，任何想法我怎么能这样做？

Answer 1

Try this

select substring(name from 1 for 12) from your_table

Referred https://www.postgresql.org/docs/9.1/static/functions-string.html

Or the comment mentioned by @Prdp is a better alternative I think. Check the cost for both and use the one suits you.