> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/15/client-interfaces/ecpg-embedded-sql-in-c/35.14.-embedded-sql-commands/ecpg-sql-describe.md).

# DESCRIBE

## DESCRIBE

DESCRIBE — obtain information about a prepared statement or result set

### Synopsis

```

DESCRIBE [ OUTPUT ] prepared_name USING [ SQL ] DESCRIPTOR descriptor_name
DESCRIBE [ OUTPUT ] prepared_name INTO [ SQL ] DESCRIPTOR descriptor_name
DESCRIBE [ OUTPUT ] prepared_name INTO sqlda_name
```

### Description

`DESCRIBE` retrieves metadata information about the result columns contained in a prepared statement, without actually fetching a row.

### Parameters

*`prepared_name`*

The name of a prepared statement. This can be an SQL identifier or a host variable.

*`descriptor_name`*

A descriptor name. It is case sensitive. It can be an SQL identifier or a host variable.

*`sqlda_name`*

The name of an SQLDA variable.

### Examples

```

EXEC SQL ALLOCATE DESCRIPTOR mydesc;
EXEC SQL PREPARE stmt1 FROM :sql_stmt;
EXEC SQL DESCRIBE stmt1 INTO SQL DESCRIPTOR mydesc;
EXEC SQL GET DESCRIPTOR mydesc VALUE 1 :charvar = NAME;
EXEC SQL DEALLOCATE DESCRIPTOR mydesc;
```

### Compatibility

`DESCRIBE` is specified in the SQL standard.

### See Also

[ALLOCATE DESCRIPTOR](/15/client-interfaces/ecpg-embedded-sql-in-c/35.14.-embedded-sql-commands/ecpg-sql-allocate-descriptor.md), [GET DESCRIPTOR](/15/client-interfaces/ecpg-embedded-sql-in-c/35.14.-embedded-sql-commands/ecpg-sql-get-descriptor.md)

***

原文：[PostgreSQL 15.19 Documentation](/15/client-interfaces/ecpg-embedded-sql-in-c/35.14.-embedded-sql-commands/ecpg-sql-describe.md)（英文原文，待翻譯）


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