Python Psycopg2 callproc和sql参数
我有一些SQL函数Python Psycopg2 callproc和sql参数,python,psycopg2,plpgsql,Python,Psycopg2,Plpgsql,我有一些SQL函数 CREATE OR REPLACE FUNCTION tools.update_company(IN company_id integer, OUT value integer) RETURNS integer AS $BODY$ BEGIN select * into value from function_making_int(company_id) END;$BODY$ 从Psycopg2(如果这很重要的话,它在Django内部)我知道 但函数返回的输
CREATE OR REPLACE FUNCTION tools.update_company(IN company_id integer, OUT value integer)
RETURNS integer AS
$BODY$
BEGIN
select * into value from function_making_int(company_id)
END;$BODY$
从Psycopg2(如果这很重要的话,它在Django内部)我知道
但函数返回的输入序列和我给出的完全相同,忽略结果和OUT参数。更改为IN-OUT并传递一些foo值不会改变任何内容。当在数据库中调用SQL函数时,该函数按预期工作我做了很少的研究,并且检查了psycopg2代码-该函数的当前实现就是这样
select * from function_name(params)
return params
因此,它不会以任何方式修改任何内容。摘自pyscopg2源代码,使用C-api的callproc的C实现给出以下代码:
/* callproc method - execute a stored procedure */
#define psyco_curs_callproc_doc \
"callproc(procname, parameters=None) -- Execute stored procedure."
static PyObject *
psyco_curs_callproc(cursorObject *self, PyObject *args)
{
const char *procname = NULL;
char *sql = NULL;
Py_ssize_t procname_len, i, nparameters = 0, sl = 0;
PyObject *parameters = Py_None;
PyObject *operation = NULL;
PyObject *res = NULL;
if (!PyArg_ParseTuple(args, "s#|O",
&procname, &procname_len, ¶meters
))
{ goto exit; }
EXC_IF_CURS_CLOSED(self);
EXC_IF_ASYNC_IN_PROGRESS(self, callproc);
EXC_IF_TPC_PREPARED(self->conn, callproc);
if (self->name != NULL) {
psyco_set_error(ProgrammingError, self,
"can't call .callproc() on named cursors");
goto exit;
}
if (parameters != Py_None) {
if (-1 == (nparameters = PyObject_Length(parameters))) { goto exit; }
}
/* allocate some memory, build the SQL and create a PyString from it */
sl = procname_len + 17 + nparameters*3 - (nparameters ? 1 : 0);
sql = (char*)PyMem_Malloc(sl);
if (sql == NULL) {
PyErr_NoMemory();
goto exit;
}
sprintf(sql, "SELECT * FROM %s(", procname);
for(i=0; i<nparameters; i++) {
strcat(sql, "%s,");
}
sql[sl-2] = ')';
sql[sl-1] = '\0';
if (!(operation = Bytes_FromString(sql))) { goto exit; }
if (0 <= _psyco_curs_execute(self, operation, parameters,
self->conn->async, 0)) {
Py_INCREF(parameters);
res = parameters;
}
exit:
Py_XDECREF(operation);
PyMem_Free((void*)sql);
return res;
}
是的,实际上代码会在地面上生成一个“选择”SQL来执行操作
/* callproc method - execute a stored procedure */
#define psyco_curs_callproc_doc \
"callproc(procname, parameters=None) -- Execute stored procedure."
static PyObject *
psyco_curs_callproc(cursorObject *self, PyObject *args)
{
const char *procname = NULL;
char *sql = NULL;
Py_ssize_t procname_len, i, nparameters = 0, sl = 0;
PyObject *parameters = Py_None;
PyObject *operation = NULL;
PyObject *res = NULL;
if (!PyArg_ParseTuple(args, "s#|O",
&procname, &procname_len, ¶meters
))
{ goto exit; }
EXC_IF_CURS_CLOSED(self);
EXC_IF_ASYNC_IN_PROGRESS(self, callproc);
EXC_IF_TPC_PREPARED(self->conn, callproc);
if (self->name != NULL) {
psyco_set_error(ProgrammingError, self,
"can't call .callproc() on named cursors");
goto exit;
}
if (parameters != Py_None) {
if (-1 == (nparameters = PyObject_Length(parameters))) { goto exit; }
}
/* allocate some memory, build the SQL and create a PyString from it */
sl = procname_len + 17 + nparameters*3 - (nparameters ? 1 : 0);
sql = (char*)PyMem_Malloc(sl);
if (sql == NULL) {
PyErr_NoMemory();
goto exit;
}
sprintf(sql, "SELECT * FROM %s(", procname);
for(i=0; i<nparameters; i++) {
strcat(sql, "%s,");
}
sql[sl-2] = ')';
sql[sl-1] = '\0';
if (!(operation = Bytes_FromString(sql))) { goto exit; }
if (0 <= _psyco_curs_execute(self, operation, parameters,
self->conn->async, 0)) {
Py_INCREF(parameters);
res = parameters;
}
exit:
Py_XDECREF(operation);
PyMem_Free((void*)sql);
return res;
}
c = connection.cursor()
res = c.callproc('tools.update_company', [1, ])