Postgresql 中文操作指南
SPI_cursor_open_with_args
SPI_cursor_open_with_args — 使用查询和参数设置游标
SPI_cursor_open_with_args — set up a cursor using a query and parameters
Synopsis
Portal SPI_cursor_open_with_args(const char *name,
const char *command,
int nargs, Oid *argtypes,
Datum *values, const char *nulls,
bool read_only, int cursorOptions)Description
SPI_cursor_open_with_args 设置将执行指定查询的游标（在内部，一个门户）。大部分参数具有与 SPI_prepare_cursor 和 SPI_cursor_open 中相应参数相同的含义。
SPI_cursor_open_with_args sets up a cursor (internally, a portal) that will execute the specified query. Most of the parameters have the same meanings as the corresponding parameters to SPI_prepare_cursor and SPI_cursor_open.
对于一次性查询执行，此函数应优于 SPI_prepare_cursor ，后跟 SPI_cursor_open 。如果使用许多不同的参数执行同一个命令，任何一个方法都可能更快，具体取决于重新规划的成本与自定义规划的好处。
For one-time query execution, this function should be preferred over SPI_prepare_cursor followed by SPI_cursor_open. If the same command is to be executed with many different parameters, either method might be faster, depending on the cost of re-planning versus the benefit of custom plans.
传入的参数数据将被复制到光标的门户中，因此可在光标仍然存在时释放它。
The passed-in parameter data will be copied into the cursor’s portal, so it can be freed while the cursor still exists.
此函数目前已弃用，因为 SPI_cursor_parse_open 取而代之，它使用更现代的 API 来处理查询参数，提供等效的功能。
This function is now deprecated in favor of SPI_cursor_parse_open, which provides equivalent functionality using a more modern API for handling query parameters.
Arguments
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const char * _name_
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name for portal, or NULL to let the system select a name
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const char * _command_
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command string
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int _nargs_
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number of input parameters ($1, $2, etc.)
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Oid * _argtypes_
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an array of length nargs, containing the OIDs of the data types of the parameters
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Datum * _values_
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an array of length nargs, containing the actual parameter values
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const char * _nulls_
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an array of length nargs, describing which parameters are null
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If nulls is NULL then SPI_cursor_open_with_args assumes that no parameters are null. Otherwise, each entry of the nulls array should be ' ' if the corresponding parameter value is non-null, or 'n' if the corresponding parameter value is null. (In the latter case, the actual value in the corresponding values entry doesn’t matter.) Note that nulls is not a text string, just an array: it does not need a '\0' terminator.
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bool _read_only_
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true for read-only execution
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int _cursorOptions_
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integer bit mask of cursor options; zero produces default behavior
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