Help Center/ GaussDB/ Developer Guide(Centralized_V2.0-8.x)/ Application Development Guide/ Development Based on libpq/ libpq Interface Reference/ Asynchronous Command Processing Functions/ PQsendQueryPrepared
Updated on 2025-05-29 GMT+08:00
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PQsendQueryPrepared

Description

Sends a request to execute a prepared statement with given parameters, without waiting for the result.

Prototype

int PQsendQueryPrepared(PGconn* conn, const char* stmtName, int nParams, const char* const* paramValues,
    const int* paramLengths, const int* paramFormats, int resultFormat);

Parameters

Table 1 PQsendQueryPrepared parameters

Keyword

Description

conn

Points to the object pointer that contains the connection information.

stmtName

Name of a prepared statement to be executed.

nParams

Parameter quantity.

paramValues

Parameter value.

paramLengths

Parameter length.

NOTICE:

In the following cases, the parameter length is forcibly set to the corresponding value of paramLengths:

  • The parameter is in binary format.
  • The parameter is in text format and the value of force_no_truncation is 1.

In these cases, paramLengths cannot be empty, and the caller must ensure the correctness of the parameter length.

paramFormats

Parameter format.

resultFormat

Result format.

Return Values

int indicates the execution result. 1 indicates successful execution and 0 indicates an execution failure. The failure cause is stored in conn->errorMessage.

Precautions

This function is similar to PQsendQueryParams, but the command to be executed is specified by naming a previously-prepared statement, instead of providing a query string. The parameters of this function are processed in the same way as PQexecPrepared. Like PQexecPrepared, it cannot work on connections using protocol v2.0.