Re: Error in SPI_execute_plan (when inserting JSON from C code first { simboll is lost)

Hi,

On 2017-06-27 01:21:04 +0300, Арсен Арутюнян wrote:
> Oid * Types = (Oid *)palloc(2 * sizeof(Oid));
> Types[0] = 23; //Int32
> Types[1] = 114; //JSON
> m_JsonInsertPlan = SPI_saveplan(SPI_prepare("insert into json_test(Num,Obj) values ($1,$2)\0", 2, Types));

So the type of what you're inserting is int and json. The latter is a
variable length type. But then you do:

> Values[0] = Int32GetDatum(227);
> Values[1] = CStringGetDatum(JsonObject->data);
> int ret = SPI_execute_plan(m_JsonInsertPlan, Values, NULL, false, 0);

inserting a cstring, rather than a json value. I.e. the issue is that
you're "lying" about the types, and their validity. You should either
use text as the plan input, and cast the result of the statement, or you
need to actually construct a proper datum, using OidInputFunctionCall or
json_in directly.

> m_JsonInsertPlan = SPI_saveplan(SPI_prepare("insert into json_test(Num,Obj) values ($1,$2)\0", 2, Types));

Not sure what that \0 is supposed to do here?

> Types[1] = 114; //JSON

You should probably include catalog/pg_type.h and use JSONOID etc.

Andres