diff options
Diffstat (limited to 'src/backend/parser')
| -rw-r--r-- | src/backend/parser/gram.y | 65 | ||||
| -rw-r--r-- | src/backend/parser/parse_expr.c | 181 |
2 files changed, 244 insertions, 2 deletions
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 945a9ada8bd..a324983f5d8 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -636,6 +636,14 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); %type <defelt> hash_partbound_elem +%type <node> json_format_clause_opt + json_representation + json_value_expr + json_output_clause_opt + +%type <ival> json_encoding + json_encoding_clause_opt + /* * Non-keyword token types. These are hard-wired into the "flex" lexer. * They must be listed first so that their numeric codes do not depend on @@ -687,7 +695,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); EXTENSION EXTERNAL EXTRACT FALSE_P FAMILY FETCH FILTER FINALIZE FIRST_P FLOAT_P FOLLOWING FOR - FORCE FOREIGN FORWARD FREEZE FROM FULL FUNCTION FUNCTIONS + FORCE FOREIGN FORMAT FORWARD FREEZE FROM FULL FUNCTION FUNCTIONS GENERATED GLOBAL GRANT GRANTED GREATEST GROUP_P GROUPING GROUPS @@ -698,7 +706,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); INNER_P INOUT INPUT_P INSENSITIVE INSERT INSTEAD INT_P INTEGER INTERSECT INTERVAL INTO INVOKER IS ISNULL ISOLATION - JOIN + JOIN JSON KEY @@ -782,6 +790,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); /* Precedence: lowest to highest */ %nonassoc SET /* see relation_expr_opt_alias */ +%right FORMAT %left UNION EXCEPT %left INTERSECT %left OR @@ -15269,6 +15278,54 @@ opt_asymmetric: ASYMMETRIC | /*EMPTY*/ ; +/* SQL/JSON support */ + +json_value_expr: + a_expr json_format_clause_opt + { + $$ = (Node *) makeJsonValueExpr((Expr *) $1, $2); + } + ; + +json_format_clause_opt: + FORMAT json_representation + { + $$ = $2; + $$.location = @1; + } + | /* EMPTY */ + { + $$ = (Node *) makeJsonFormat(JS_FORMAT_DEFAULT, JS_ENC_DEFAULT, -1); + } + ; + +json_representation: + JSON json_encoding_clause_opt + { + $$ = (Node *) makeJsonFormat(JS_FORMAT_JSON, $2, @1); + } + /* | other implementation defined JSON representation options (BSON, AVRO etc) */ + ; + +json_encoding_clause_opt: + ENCODING json_encoding { $$ = $2; } + | /* EMPTY */ { $$ = JS_ENC_DEFAULT; } + ; + +json_encoding: + name { $$ = makeJsonEncoding($1); } + ; + +json_output_clause_opt: + RETURNING Typename json_format_clause_opt + { + JsonOutput *n = makeNode(JsonOutput); + n->typeName = $2; + n->returning.format = $3; + $$ = (Node *) n; + } + | /* EMPTY */ { $$ = NULL; } + ; /***************************************************************************** * @@ -15810,6 +15867,7 @@ unreserved_keyword: | FIRST_P | FOLLOWING | FORCE + | FORMAT | FORWARD | FUNCTION | FUNCTIONS @@ -15841,6 +15899,7 @@ unreserved_keyword: | INSTEAD | INVOKER | ISOLATION + | JSON | KEY | LABEL | LANGUAGE @@ -16357,6 +16416,7 @@ bare_label_keyword: | FOLLOWING | FORCE | FOREIGN + | FORMAT | FORWARD | FREEZE | FULL @@ -16401,6 +16461,7 @@ bare_label_keyword: | IS | ISOLATION | JOIN + | JSON | KEY | LABEL | LANGUAGE diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 1c09ea24cdf..985ddbedf11 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -34,6 +34,7 @@ #include "parser/parse_type.h" #include "utils/builtins.h" #include "utils/date.h" +#include "utils/fmgroids.h" #include "utils/lsyscache.h" #include "utils/timestamp.h" #include "utils/xml.h" @@ -3099,3 +3100,183 @@ ParseExprKindName(ParseExprKind exprKind) } return "unrecognized expression kind"; } + +/* + * Make string Const node from JSON encoding name. + * + * UTF8 is default encoding. + */ +static Const * +getJsonEncodingConst(JsonFormat *format) +{ + JsonEncoding encoding; + const char *enc; + Name encname = palloc(sizeof(NameData)); + + if (!format || + format->format_type == JS_FORMAT_DEFAULT || + format->encoding == JS_ENC_DEFAULT) + encoding = JS_ENC_UTF8; + else + encoding = format->encoding; + + switch (encoding) + { + case JS_ENC_UTF16: + enc = "UTF16"; + break; + case JS_ENC_UTF32: + enc = "UTF32"; + break; + case JS_ENC_UTF8: + enc = "UTF8"; + break; + default: + elog(ERROR, "invalid JSON encoding: %d", encoding); + break; + } + + namestrcpy(encname, enc); + + return makeConst(NAMEOID, -1, InvalidOid, NAMEDATALEN, + NameGetDatum(encname), false, false); +} + +/* + * Make bytea => text conversion using specified JSON format encoding. + */ +static Node * +makeJsonByteaToTextConversion(Node *expr, JsonFormat *format, int location) +{ + Const *encoding = getJsonEncodingConst(format); + FuncExpr *fexpr = makeFuncExpr(F_CONVERT_FROM, TEXTOID, + list_make2(expr, encoding), + InvalidOid, InvalidOid, + COERCE_EXPLICIT_CALL); + + fexpr->location = location; + + return (Node *) fexpr; +} + +/* + * Make CaseTestExpr node. + */ +static Node * +makeCaseTestExpr(Node *expr) +{ + CaseTestExpr *placeholder = makeNode(CaseTestExpr); + + placeholder->typeId = exprType(expr); + placeholder->typeMod = exprTypmod(expr); + placeholder->collation = exprCollation(expr); + + return (Node *) placeholder; +} + +/* + * Transform JSON value expression using specified input JSON format or + * default format otherwise. + */ +static Node * +transformJsonValueExpr(ParseState *pstate, JsonValueExpr *ve, + JsonFormatType default_format) +{ + Node *expr = transformExprRecurse(pstate, (Node *) ve->raw_expr); + Node *rawexpr; + JsonFormatType format; + Oid exprtype; + int location; + char typcategory; + bool typispreferred; + + if (exprType(expr) == UNKNOWNOID) + expr = coerce_to_specific_type(pstate, expr, TEXTOID, "JSON_VALUE_EXPR"); + + rawexpr = expr; + exprtype = exprType(expr); + location = exprLocation(expr); + + get_type_category_preferred(exprtype, &typcategory, &typispreferred); + + if (ve->format->format_type != JS_FORMAT_DEFAULT) + { + if (ve->format->encoding != JS_ENC_DEFAULT && exprtype != BYTEAOID) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("JSON ENCODING clause is only allowed for bytea input type"), + parser_errposition(pstate, ve->format->location))); + + if (exprtype == JSONOID || exprtype == JSONBOID) + { + format = JS_FORMAT_DEFAULT; /* do not format json[b] types */ + ereport(WARNING, + (errmsg("FORMAT JSON has no effect for json and jsonb types"), + parser_errposition(pstate, ve->format->location))); + } + else + format = ve->format->format_type; + } + else if (exprtype == JSONOID || exprtype == JSONBOID) + format = JS_FORMAT_DEFAULT; /* do not format json[b] types */ + else + format = default_format; + + if (format != JS_FORMAT_DEFAULT) + { + Oid targettype = format == JS_FORMAT_JSONB ? JSONBOID : JSONOID; + Node *orig = makeCaseTestExpr(expr); + Node *coerced; + + expr = orig; + + if (exprtype != BYTEAOID && typcategory != TYPCATEGORY_STRING) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg(ve->format->format_type == JS_FORMAT_DEFAULT ? + "cannot use non-string types with implicit FORMAT JSON clause" : + "cannot use non-string types with explicit FORMAT JSON clause"), + parser_errposition(pstate, ve->format->location >= 0 ? + ve->format->location : location))); + + /* Convert encoded JSON text from bytea. */ + if (format == JS_FORMAT_JSON && exprtype == BYTEAOID) + { + expr = makeJsonByteaToTextConversion(expr, ve->format, location); + exprtype = TEXTOID; + } + + /* Try to coerce to the target type. */ + coerced = coerce_to_target_type(pstate, expr, exprtype, + targettype, -1, + COERCION_EXPLICIT, + COERCE_EXPLICIT_CAST, + location); + + if (!coerced) + { + /* If coercion failed, use to_json()/to_jsonb() functions. */ + Oid fnoid = targettype == JSONOID ? F_TO_JSON : F_TO_JSONB; + FuncExpr *fexpr = makeFuncExpr(fnoid, targettype, + list_make1(expr), + InvalidOid, InvalidOid, + COERCE_EXPLICIT_CALL); + fexpr->location = location; + + coerced = (Node *) fexpr; + } + + if (coerced == orig) + expr = rawexpr; + else + { + ve = copyObject(ve); + ve->raw_expr = (Expr *) rawexpr; + ve->formatted_expr = (Expr *) coerced; + + expr = (Node *) ve; + } + } + + return expr; +} |