postgresql - Postgres : how to excecute the query for Sum as it is giving error?

Question

我正在使用 sum 函数求总数但出现错误。这是查询:

select sum(col1) 
from table_name 
where col2="abc"

Error: function sum(text) does not exist
Hint: No function matches the given name and argument types. You might need to add explicit type casts

Answer 1

假设 text 列包含 text 数字，而不是实际整数，那么它将解释您看到的错误。您可以通过首先将 text 转换为整数，然后求和来解决这个问题:

SELECT SUM(text::int)
FROM yourTable;