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| author | Andrew Dunstan <andrew@dunslane.net> | 2022-03-03 13:11:14 -0500 |
|---|---|---|
| committer | Andrew Dunstan <andrew@dunslane.net> | 2022-03-29 16:57:13 -0400 |
| commit | 1a36bc9dba8eae90963a586d37b6457b32b2fed4 (patch) | |
| tree | eeb155046082dda9284bd8c298874d802bcc37cb /src/include/utils/jsonpath.h | |
| parent | 3d067c53b26dfeb95da0d75a65614b4d7b45c317 (diff) | |
| download | postgresql-1a36bc9dba8eae90963a586d37b6457b32b2fed4.tar.gz postgresql-1a36bc9dba8eae90963a586d37b6457b32b2fed4.zip | |
SQL/JSON query functions
This introduces the SQL/JSON functions for querying JSON data using
jsonpath expressions. The functions are:
JSON_EXISTS()
JSON_QUERY()
JSON_VALUE()
All of these functions only operate on jsonb. The workaround for now is
to cast the argument to jsonb.
JSON_EXISTS() tests if the jsonpath expression applied to the jsonb
value yields any values. JSON_VALUE() must return a single value, and an
error occurs if it tries to return multiple values. JSON_QUERY() must
return a json object or array, and there are various WRAPPER options for
handling scalar or multi-value results. Both these functions have
options for handling EMPTY and ERROR conditions.
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
Diffstat (limited to 'src/include/utils/jsonpath.h')
| -rw-r--r-- | src/include/utils/jsonpath.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/include/utils/jsonpath.h b/src/include/utils/jsonpath.h index cd0b5d5b61c..98a61d7f72f 100644 --- a/src/include/utils/jsonpath.h +++ b/src/include/utils/jsonpath.h @@ -16,7 +16,9 @@ #include "fmgr.h" #include "nodes/pg_list.h" +#include "nodes/primnodes.h" #include "utils/jsonb.h" +#include "utils/jsonfuncs.h" typedef struct { @@ -174,6 +176,7 @@ extern bool jspGetBool(JsonPathItem *v); extern char *jspGetString(JsonPathItem *v, int32 *len); extern bool jspGetArraySubscript(JsonPathItem *v, JsonPathItem *from, JsonPathItem *to, int i); +extern bool jspIsMutable(JsonPath *path, List *varnames, List *varexprs); extern const char *jspOperationName(JsonPathItemType type); @@ -248,4 +251,34 @@ extern JsonPathParseResult *parsejsonpath(const char *str, int len); extern int jspConvertRegexFlags(uint32 xflags); +/* + * Evaluation of jsonpath + */ + +/* External variable passed into jsonpath. */ +typedef struct JsonPathVariableEvalContext +{ + char *name; + Oid typid; + int32 typmod; + struct ExprContext *econtext; + struct ExprState *estate; + Datum value; + bool isnull; + bool evaluated; +} JsonPathVariableEvalContext; + +/* SQL/JSON item */ +extern void JsonItemFromDatum(Datum val, Oid typid, int32 typmod, + JsonbValue *res); + +extern bool JsonPathExists(Datum jb, JsonPath *path, List *vars, bool *error); +extern Datum JsonPathQuery(Datum jb, JsonPath *jp, JsonWrapper wrapper, + bool *empty, bool *error, List *vars); +extern JsonbValue *JsonPathValue(Datum jb, JsonPath *jp, bool *empty, + bool *error, List *vars); + +extern int EvalJsonPathVar(void *vars, char *varName, int varNameLen, + JsonbValue *val, JsonbValue *baseObject); + #endif |