Question

我试图在google中搜索我的sql语句有什么问题，但没有成功！

[Err] ERROR：运算符不存在：字符变化*字符变化   第16行：“数量”*“单价”为“总计”

提示：没有运算符匹配给定的名称和参数类型。您可能需要添加显式类型转换。

SELECT
"Trade Date",
"Due Date",
"Reference",
"Type",
"Symbol",
to_number("Quantity", '99999999D99')AS "Quantity",
to_number("Unit Price", '99999999D99')AS "Unit Price",
to_number("Amount", '99999999D99')AS "Amount",
to_number("Commission", '99999999D99')AS "Commission",
to_number("Charge", '99999999D99')AS "Charge",
to_number("VAT", '99999999D99')AS "VAT",
to_number("Net Amount", '99999999D99')AS "Net Amount",
"W/H",
to_number("Net Price", '99999999D99')AS "Net Price",
"Quantity" * "Unit Price" as "Total"

FROM
"public".aa

Answer 1

您无法在定义它的同一级别使用列别名。因此，表达式"Quantity"中对"Quantity" * "Unit Price"的引用是指实际（varchar）列，而不是您定义的别名。

如果要访问别名的值，则需要使用派生表：

SELECT "Trade Date",
       "Due Date",
       "Reference",
       "Type",
       "Symbol",
        "Quantity",
        "Unit Price",
        "Amount",
        "Commission",
        "Charge",
        "VAT",
        "Net Amount",
        "W/H",
        "Net Price",
        "Quantity" * "Unit Price" as "Total"
FROM (
  SELECT "Trade Date",
         "Due Date",
         "Reference",
         "Type",
         "Symbol",
          to_number("Quantity", '99999999D99') AS "Quantity",
          to_number("Unit Price", '99999999D99') AS "Unit Price",
          to_number("Amount", '99999999D99') AS "Amount",
          to_number("Commission", '99999999D99') AS "Commission",
          to_number("Charge", '99999999D99') AS "Charge",
          to_number("VAT", '99999999D99')  AS "VAT",
          to_number("Net Amount", '99999999D99') AS "Net Amount",
          "W/H",
          to_number("Net Price", '99999999D99')AS "Net Price"
  FROM "public".aa        
) t

然而，更好的解决方案是不在varchar列中存储数字。数字应存储在定义为numeric或integer

的列中定义为varchar或text，从不的列中

没有运算符匹配给定的名称和参数类型

1 个答案: