该怎么写代码来判断？

[FlyingQQ]

我要判断某个字段是否为空，该怎么写代码？

[FlyingQQ]

数据库为SQL SERVER 2000，用adotable连接。

[tianjin]

Field.IsNull: Boolean

[prometheusphinx]

TField.IsNull

[tianjin]

SELECT *
FROM TableName WHERE Field IS NULL

[FlyingQQ]

详细点！可以吗？

[NetLoLo]

if query.fieldbyname('field').IsNull then...else...

[intothe_rain]

Field.IsNull: Boolean

[intothe_rain]

同意

[King_Dragon]

摘自delphi5bde local sql help：
Indicates whether a column contains a NULL value.
column_reference IS [NOT] NULL
Description
Use the IS NULL comparison predicate to filter a table based on the specified column containing a NULL (empty) value.
SELECT *
FROM Customer
WHERE (InvoiceDate IS NULL)
Use NOT to return the converse of a IS NULL comparison.
Note For a numeric column, a zero value is not the same as a NULL value.