连字符在 Db2 for i 查询结果中表示什么？

Question

我想过滤掉以下查询中包含破折号的行。 PRMWT 列是 DECIMAL (9, 3).

查询

SELECT
    PPA#,
    PRMWT
FROM FUTMODS.SCPMSTQ
WHERE PPA# = '20829161'

结果

PPA#        PRMWT
20829161    53.513
20829161    -
20829161    -
20829161    -
20829161    -
20829161    -

如果我添加条件 AND PRMWT IS NOT NULL，结果是一样的，但我收到此警告：

SQL State: 01565 Vendor Code: 802 Message: [SQL0802] Data conversion or data mapping error. Cause . . . . . : Error type 6 has occurred. Error types and their meanings are: 1 -- Arithmetic overflow. 2 -- Floating point overflow. 3 -- Floating point underflow. 4 -- Floating point conversion error. 5 -- Not an exact result. 6 -- Numeric data that is not valid. 7 -- Double-byte character set (DBCS) or UTF-8 data that is not valid. 8 -- Division by zero. 9 -- Hash value cannot be computed for the requested query. 10 -- User-defined function returned a mapping error. 11 -- Not valid length found in a varying-length column returned from an array result set. 12 -- Result of a concatenation operation on a varying-length field exceeded the maximum allowed length of the result type. If the error occurred when assigning a value to a host variable of a FETCH, embedded SELECT, SET, or VALUES INTO statement, the host variable name is *N and the relative position of the host variable in the INTO clause is 2. If the host variable name is *N, the error occurred when attempting to resolve a search condition. If more than one data mapping error occurred, this is a description of the first error that occurred. For a description of any other data mapping errors, see the previously listed messages in the job log. Recovery . . . : The error was caused by data that was not valid or that was too large. Look at the previously listed messages in the job log (DSPJOBLOG command) or press F10 (Display messages in job log) on this display to determine what row and columns were involved in the error. Correct the data and then try the request again.

仔细检查后，我看到该列有 Nullable = No。好的，但是为什么它里面有非数字的东西（连字符）？

我也试过PRMWT > 0, PRMWT > 0.0, PRMWT > '000000.000', PRMWT != '-', PRMWT != '', PRMWT = CAST(0.0 AS DECIMAL(9,3)), CAST(PRMWT AS FLOAT) > 0.0,等等

我迷路了。在这个被遗忘的数据库引擎中，连字符到底意味着什么？我该如何操作它？ OS 是版本 7.2。

Answer 1

使用hex函数查找PRMWT字段中的十进制数据错误：

SELECT  PPA#, hex(PRMWT) hex_prmwt
FROM FUTMODS.SCPMSTQ
WHERE PPA# = '20829161'

要更正错误数据，您可以测试特定的十六进制值并使用 SQL UPDATE 将字段设置为 0。

update FUTMODS.SCPMSTQ
set    PRMWT = 0
where  hex(PRMWT) = '404040'

这是一篇好文章：https://www.itjungle.com/2013/08/07/fhg080713-story02/

连字符在 Db2 for i 查询结果中表示什么？

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