| title | INSERT Statement Limitations | Microsoft Docs | |||
|---|---|---|---|---|
| ms.custom | ||||
| ms.date | 01/19/2017 | |||
| ms.prod | sql | |||
| ms.prod_service | connectivity | |||
| ms.reviewer | ||||
| ms.technology | connectivity | |||
| ms.topic | conceptual | |||
| helpviewer_keywords |
|
|||
| ms.assetid | dea05698-527a-41ab-8729-bbed85556185 | |||
| author | David-Engel | |||
| ms.author | v-daenge |
Inserted data is truncated on the right without warning if it is too long to fit into the column.
Attempting to insert a value that is out of the range of a column's data type causes a NULL to be inserted into the column.
When a dBASE, Microsoft Excel, Paradox, or Textdriver is used, inserting a zero-length string into a column actually inserts a NULL instead.
When the Microsoft Excel driver is used, if an empty string is inserted into a column, the empty string is converted to a NULL; a searched SELECT statement that is executed with an empty string in the WHERE clause will not succeed on that column.
A table is not updatable by the Paradox driver under two conditions:
-
When a unique index is not defined on the table. This is not true for an empty table, which can be updated with a single row even if a unique index is not defined on the table. If a single row is inserted in an empty table that does not have a unique index, an application cannot create a unique index or insert additional data after the single row has been inserted.
-
If the Borland Database Engine is not implemented, only read and append statements are allowed on the Paradox table.
When the Text driver is used, NULL values are represented by a blank-padded string in fixed-length files, but are represented by no spaces in delimited files. For example, in the following row containing three fields, the second field is a NULL value:
"Smith:,, 123
When the Text driver is used, all column values can be padded with leading spaces. The length of any row must be less than or equal to 65,543 bytes.