From cba58ec1410eb99fc974d8a46013ce7331c93377 Mon Sep 17 00:00:00 2001 From: Nikita Glukhov Date: Fri, 3 Nov 2017 14:15:51 +0300 Subject: [PATCH] Allow variable jsonpath specifications --- src/backend/executor/execExpr.c | 7 +++++++ src/backend/executor/execExprInterp.c | 5 ++--- src/backend/nodes/copyfuncs.c | 2 +- src/backend/parser/gram.y | 11 ++++++----- src/backend/parser/parse_clause.c | 35 ++++++++++++++++++++++++++++++----- src/backend/parser/parse_expr.c | 19 +++++++++++++------ src/backend/utils/adt/ruleutils.c | 11 +++++++++-- src/include/executor/execExpr.h | 3 ++- src/include/nodes/parsenodes.h | 2 +- src/include/nodes/primnodes.h | 2 +- 10 files changed, 72 insertions(+), 25 deletions(-) diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c index 3cc8e12..86030b9 100644 --- a/src/backend/executor/execExpr.c +++ b/src/backend/executor/execExpr.c @@ -2042,6 +2042,13 @@ ExecInitExprRec(Expr *node, PlanState *parent, ExprState *state, &scratch.d.jsonexpr.raw_expr->value, &scratch.d.jsonexpr.raw_expr->isnull); + scratch.d.jsonexpr.pathspec = + palloc(sizeof(*scratch.d.jsonexpr.pathspec)); + + ExecInitExprRec((Expr *) jexpr->path_spec, parent, state, + &scratch.d.jsonexpr.pathspec->value, + &scratch.d.jsonexpr.pathspec->isnull); + scratch.d.jsonexpr.formatted_expr = ExecInitExpr((Expr *) jexpr->formatted_expr, parent); diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c index b9d719d..36ef0fd 100644 --- a/src/backend/executor/execExprInterp.c +++ b/src/backend/executor/execExprInterp.c @@ -3897,7 +3897,7 @@ ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext) *op->resnull = true; /* until we get a result */ *op->resvalue = (Datum) 0; - if (op->d.jsonexpr.raw_expr->isnull) + if (op->d.jsonexpr.raw_expr->isnull || op->d.jsonexpr.pathspec->isnull) { /* execute domain checks for NULLs */ (void) ExecEvalJsonExprCoercion(op, econtext, res, op->resnull, isjsonb); @@ -3905,8 +3905,7 @@ ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext) } item = op->d.jsonexpr.raw_expr->value; - - path = DatumGetJsonPath(jexpr->path_spec->constvalue); + path = DatumGetJsonPath(op->d.jsonexpr.pathspec->value); /* reset JSON path variable contexts */ foreach(lc, op->d.jsonexpr.args) diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c index 80c0e48..34fed1d 100644 --- a/src/backend/nodes/copyfuncs.c +++ b/src/backend/nodes/copyfuncs.c @@ -2332,7 +2332,7 @@ _copyJsonCommon(const JsonCommon *from) JsonCommon *newnode = makeNode(JsonCommon); COPY_NODE_FIELD(expr); - COPY_STRING_FIELD(pathspec); + COPY_NODE_FIELD(pathspec); COPY_STRING_FIELD(pathname); COPY_NODE_FIELD(passing); COPY_LOCATION_FIELD(location); diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index adfe9b1..71a59d1 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -624,6 +624,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); json_table_plan_cross json_table_plan_primary json_table_default_plan + json_path_specification %type json_arguments json_passing_clause_opt @@ -635,8 +636,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); %type json_returning_clause_opt -%type json_path_specification - json_table_column_path_specification_clause_opt +%type json_table_column_path_specification_clause_opt json_table_path_name json_as_path_name_clause_opt @@ -845,6 +845,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); */ %nonassoc UNBOUNDED /* ideally should have same precedence as IDENT */ %nonassoc ERROR_P EMPTY_P DEFAULT ABSENT /* JSON error/empty behavior */ +%nonassoc COLUMNS FALSE_P KEEP OMIT PASSING TRUE_P UNKNOWN %nonassoc IDENT GENERATED NULL_P PARTITION RANGE ROWS PRECEDING FOLLOWING CUBE ROLLUP %left Op OPERATOR /* multi-character ops and user-defined operators */ %left '+' '-' @@ -14472,7 +14473,7 @@ json_context_item: ; json_path_specification: - Sconst { $$ = $1; } + a_expr { $$ = $1; } ; json_as_path_name_clause_opt: @@ -14770,7 +14771,7 @@ json_table_error_clause_opt: ; json_table_column_path_specification_clause_opt: - PATH json_path_specification { $$ = $2; } + PATH Sconst { $$ = $2; } | /* EMPTY */ %prec json_table_column { $$ = NULL; } ; @@ -14802,7 +14803,7 @@ json_table_formatted_column_definition: ; json_table_nested_columns: - NESTED path_opt json_path_specification + NESTED path_opt Sconst json_as_path_name_clause_opt json_table_columns_clause { diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index 227925e..fe9cb30 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -1088,6 +1088,18 @@ transformRangeTableSample(ParseState *pstate, RangeTableSample *rts) return tablesample; } +static Node * +makeStringConst(char *str, int location) +{ + A_Const *n = makeNode(A_Const); + + n->val.type = T_String; + n->val.val.str = str; + n->location = location; + + return (Node *)n; +} + /* * Transform JSON_TABLE column * - regular column into JSON_VALUE() @@ -1101,6 +1113,7 @@ transformJsonTableColumn(JsonTableColumn *jtc, Node *contextItemExpr, JsonValueExpr *jvexpr = makeNode(JsonValueExpr); JsonCommon *common = makeNode(JsonCommon); JsonOutput *output = makeNode(JsonOutput); + JsonPathSpec pathspec; jfexpr->op = jtc->coltype == JTC_REGULAR ? IS_JSON_VALUE : IS_JSON_QUERY; jfexpr->common = common; @@ -1121,7 +1134,7 @@ transformJsonTableColumn(JsonTableColumn *jtc, Node *contextItemExpr, common->passing = passingArgs; if (jtc->pathspec) - common->pathspec = jtc->pathspec; + pathspec = jtc->pathspec; else { /* Construct default path as '$."column_name"' */ @@ -1132,9 +1145,11 @@ transformJsonTableColumn(JsonTableColumn *jtc, Node *contextItemExpr, appendStringInfoString(&path, "$."); escape_json(&path, jtc->name); - common->pathspec = path.data; + pathspec = path.data; } + common->pathspec = makeStringConst(pathspec, -1); + jvexpr->expr = (Expr *) contextItemExpr; jvexpr->format.type = JS_FORMAT_DEFAULT; jvexpr->format.encoding = JS_ENC_DEFAULT; @@ -1628,6 +1643,7 @@ transformJsonTable(ParseState *pstate, JsonTable *jt) JsonCommon *jscommon; JsonTablePlan *plan = jt->plan; char *rootPathName = jt->common->pathname; + char *rootPath; bool is_lateral; cxt.table = jt; @@ -1657,7 +1673,7 @@ transformJsonTable(ParseState *pstate, JsonTable *jt) } jscommon = copyObject(jt->common); - jscommon->pathspec = pstrdup("$"); + jscommon->pathspec = makeStringConst(pstrdup("$"), -1); jfe->op = IS_JSON_TABLE; jfe->common = jscommon; @@ -1681,10 +1697,19 @@ transformJsonTable(ParseState *pstate, JsonTable *jt) cxt.contextItemTypid = exprType(tf->docexpr); + if (!IsA(jt->common->pathspec, A_Const) || + castNode(A_Const, jt->common->pathspec)->val.type != T_String) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("only string constants supported in JSON_TABLE path specification"), + parser_errposition(pstate, + exprLocation(jt->common->pathspec)))); + + rootPath = castNode(A_Const, jt->common->pathspec)->val.val.str; + tf->plan = (Node *) transformJsonTableColumns(pstate, &cxt, plan, jt->columns, - jt->common->pathspec, - &rootPathName, + rootPath, &rootPathName, jt->common->location); tf->ordinalitycol = -1; /* undefine ordinality column number */ diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 1ec3ae4..70da19a 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -4353,7 +4353,7 @@ static JsonExpr * transformJsonExprCommon(ParseState *pstate, JsonFuncExpr *func) { JsonExpr *jsexpr = makeNode(JsonExpr); - Datum jsonpath; + Node *pathspec; JsonFormatType format; if (func->common->pathname && func->op != IS_JSON_TABLE) @@ -4383,12 +4383,19 @@ transformJsonExprCommon(ParseState *pstate, JsonFuncExpr *func) jsexpr->format = func->common->expr->format; - /* parse JSON path string */ - jsonpath = DirectFunctionCall1(jsonpath_in, - CStringGetDatum(func->common->pathspec)); + pathspec = transformExprRecurse(pstate, func->common->pathspec); - jsexpr->path_spec = makeConst(JSONPATHOID, -1, InvalidOid, -1, - jsonpath, false, false); + jsexpr->path_spec = + coerce_to_target_type(pstate, pathspec, exprType(pathspec), + JSONPATHOID, -1, + COERCION_EXPLICIT, COERCE_IMPLICIT_CAST, + exprLocation(pathspec)); + if (!jsexpr->path_spec) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("JSON path expression must be type %s, not type %s", + "jsonpath", format_type_be(exprType(pathspec))), + parser_errposition(pstate, exprLocation(pathspec)))); /* transform and coerce to json[b] passing arguments */ transformJsonPassingArgs(pstate, format, func->common->passing, diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 51c5a9d..48c7027 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -8834,7 +8834,10 @@ get_rule_expr(Node *node, deparse_context *context, appendStringInfoString(buf, ", "); - get_const_expr(jexpr->path_spec, context, -1); + if (IsA(jexpr->path_spec, Const)) + get_const_expr((Const *) jexpr->path_spec, context, -1); + else + get_rule_expr(jexpr->path_spec, context, false); if (jexpr->passing.values) { @@ -9833,7 +9836,11 @@ get_json_table_columns(TableFunc *tf, JsonTableParentNode *node, " FORMAT JSONB" : " FORMAT JSON"); appendStringInfoString(buf, " PATH "); - get_const_expr(colexpr->path_spec, context, -1); + + if (IsA(colexpr->path_spec, Const)) + get_const_expr((Const *) colexpr->path_spec, context, -1); + else + get_rule_expr(colexpr->path_spec, context, false); if (colexpr->wrapper == JSW_CONDITIONAL) appendStringInfo(buf, " WITH CONDITIONAL WRAPPER"); diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h index 96995d8..5bd4840 100644 --- a/src/include/executor/execExpr.h +++ b/src/include/executor/execExpr.h @@ -578,7 +578,8 @@ typedef struct ExprEvalStep { Datum value; bool isnull; - } *raw_expr; /* raw context item value */ + } *raw_expr, /* raw context item value */ + *pathspec; /* path specification value */ ExprState *formatted_expr; /* formatted context item */ ExprState *result_expr; /* coerced to output type */ diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index afd2d9e..630715b 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -1475,7 +1475,7 @@ typedef struct JsonCommon { NodeTag type; JsonValueExpr *expr; /* context item expression */ - JsonPathSpec pathspec; /* JSON path specification */ + Node *pathspec; /* JSON path specification expression */ char *pathname; /* path name, if any */ List *passing; /* list of PASSING clause arguments, if any */ int location; /* token location, or -1 if unknown */ diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h index 15eee2b..1b7dc27 100644 --- a/src/include/nodes/primnodes.h +++ b/src/include/nodes/primnodes.h @@ -1281,7 +1281,7 @@ typedef struct JsonExpr bool coerce_via_io; /* coerce result using type input function */ Oid coerce_via_io_collation; /* collation for conversion through I/O */ JsonFormat format; /* context item format (JSON/JSONB) */ - Const *path_spec; /* JSON path specification */ + Node *path_spec; /* JSON path specification expression */ JsonPassing passing; /* PASSING clause arguments */ JsonReturning returning; /* RETURNING clause type/format info */ JsonBehavior on_empty; /* ON EMPTY behavior */ -- 2.7.4