oracle SQL查询以获取列的精度值
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SQL query to get the precision value of a column
提问by user917670
I need a sql query that gets the precision value for certain columns.. I am mainly concerned with a decimal type column and I need the precision value for the same.
我需要一个 sql 查询来获取某些列的精度值。我主要关注十进制类型的列，我需要相同的精度值。
I realise that it is possible to do so in certain versions and vendors of database servers. It would be nice if you could list down for a few of them.
我意识到在某些版本和供应商的数据库服务器中可以这样做。如果你能列出其中的一些，那就太好了。
采纳答案by Hugh Jones
Oracle:
甲骨文：
SELECT DATA_LENGTH, DATA_PRECISION
FROM ALL_TAB_COLUMNS
WHERE TABLE_NAME = :TableName
AND COLUMN_NAME = :ColumnName
Firebird (+ Interbase) :
火鸟（+ Interbase）：
SELECT
rdb$field_scale,
rdb$field_precision
FROM rdb$relations r
JOIN rdb$relation_fields rf
ON rf.rdb$relation_name = r.rdb$relation_name
JOIN rdb$fields fld
ON rf.rdb$field_source = fld.rdb$field_name
WHERE r.rdb$relation_name = :TableName
AND rf.rdb$field_name = :ColumnName
MySql (Not Tested !) :
MySql（未测试！）：
SELECT
NUMERIC_PRECISION, NUMERIC_SCALE
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_NAME = :TableName AND
COLUMN_NAME = :ColumnName
回答by Baz1nga
for sql server:
对于 sql 服务器：
select precision from sys.columns where name='<column_name>'
for oracle:
甲骨文：
select data_precision from all_tab_columns where column_name = '<columnName>'
回答by Martin Smith
For SQL Server you can also use NUMERIC_PRECISIONin INFORMATION_SCHEMA.COLUMNS.
对于 SQL Server，您还可以NUMERIC_PRECISION在INFORMATION_SCHEMA.COLUMNS.
I assume this may well be portable.
我认为这很可能是便携式的。
回答by Andomar
For SQL Server, it's:
对于 SQL Server，它是：
select object_name(object_id), name, precision from sys.columns
回答by ain
For FireBird and InterBase
对于 FireBird 和 InterBase
SELECT
RDB$FIELD_PRECISION, RDB$FIELD_SCALE
FROM RDB$FIELDS
WHERE RDB$FIELD_NAME = columnsDomainName
