linux - 通过 bash 脚本运行时 psql 列名不存在

Question

我正在尝试在 bash 脚本中运行多个 sql 语句。我尝试在 psql 上运行以下语句，它工作正常。但是，当我在脚本上运行确切的语句时，它说该列不存在。

声明

\copy (SELECT * FROM table_a h JOIN table_b b ON h."IDX" = b."IDX" WHERE b."XXX" BETWEEN 0 AND 100) to 'D:\$path\onetry1.csv' with csv HEADER;

我知道在 Postgres 中，需要在大写列名上使用双引号。我做到了。

这是我的 bash 脚本:

#! /bin/sh

db="usm"

PGPASSWORD=XXX123 psql -h localhost -U postgres -d $db -c "\copy (SELECT * FROM table_a h JOIN table_b b ON h."IDX" = b."IDX" WHERE b."XXX" BETWEEN 0 AND 500) to '$path\onetry2.csv' with csv HEADER;"

我得到的错误:

ERROR: column h.idx does not exist LINE 1: ...M table_a h JOIN table_b b ON h.IDX = b....

Answer 1

您的 shell 脚本不发送双引号。你有这个:

"\copy (SELECT * FROM table_a h JOIN table_b b ON h."IDX" = b."IDX" WHERE b."XXX" BETWEEN 0 AND 500) to '$path\onetry2.csv' with csv HEADER;"

它本质上是作为以下字符串的串联

"\copy (SELECT * FROM table_a h JOIN table_b b ON h."
IDX
" = b."
IDX
" WHERE b."
XXX
" BETWEEN 0 AND 500) to '$path\onetry2.csv' with csv HEADER;"

但是 PostgreSQL 永远看不到双引号。使用反斜杠转义嵌套的双引号:

"\copy (SELECT * FROM table_a h JOIN table_b b ON h.\"IDX\" = b.\"IDX\" WHERE b.\"XXX\" BETWEEN 0 AND 500) to '$path\onetry2.csv' with csv HEADER;"

此外，更愿意避免强制所有大写或任何特定的大小写。如果需要，您仍然可以输入大写字母。我仅使用带引号的列名来格式化最终查询。