/*
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* For PostgreSQL Database Management System:
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* (formerly known as Postgres, then as Postgres95)
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*
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* Portions Copyright (c) 1996-2010, The PostgreSQL Global Development Group
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*
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* Portions Copyright (c) 1994, The Regents of the University of California
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*
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* Permission to use, copy, modify, and distribute this software and its documentation for any purpose,
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* without fee, and without a written agreement is hereby granted, provided that the above copyright notice
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* and this paragraph and the following two paragraphs appear in all copies.
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*
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* IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT,
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* INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY
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* OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*
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* THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA
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* HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*/
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#include "postgres.h"
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#include "nodes/makefuncs.h"
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#include "parser/parse_relation.h"
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#include "parser/parse_target.h"
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#include "parser/cypher_expr.h"
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#include "parser/cypher_item.h"
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static List *ExpandAllTables(ParseState *pstate, int location);
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static List *expand_rel_attrs(ParseState *pstate, RangeTblEntry *rte,
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int rtindex, int sublevels_up, int location);
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// see transformTargetEntry()
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TargetEntry *transform_cypher_item(cypher_parsestate *cpstate, Node *node,
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Node *expr, ParseExprKind expr_kind,
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char *colname, bool resjunk)
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{
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ParseState *pstate = (ParseState *)cpstate;
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if (!expr)
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expr = transform_cypher_expr(cpstate, node, expr_kind);
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if (!colname && !resjunk)
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colname = FigureColname(node);
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return makeTargetEntry((Expr *)expr, (AttrNumber)pstate->p_next_resno++,
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colname, resjunk);
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}
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// see transformTargetList()
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List *transform_cypher_item_list(cypher_parsestate *cpstate, List *item_list,
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List **groupClause, ParseExprKind expr_kind)
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{
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List *target_list = NIL;
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ListCell *li;
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List *group_clause = NIL;
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bool hasAgg = false;
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bool expand_star;
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expand_star = (expr_kind != EXPR_KIND_UPDATE_SOURCE);
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foreach (li, item_list)
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{
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ResTarget *item = lfirst(li);
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TargetEntry *te;
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if (expand_star)
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{
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if (IsA(item->val, ColumnRef))
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{
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ColumnRef *cref = (ColumnRef *) item->val;
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if (IsA(llast(cref->fields), A_Star))
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{
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ParseState *pstate = &cpstate->pstate;
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/* we only allow a bare '*' */
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if (list_length(cref->fields) != 1)
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{
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ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
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errmsg("Invalid number of fields for *"),
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parser_errposition(pstate,
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cref->location)));
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}
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target_list = list_concat(target_list,
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ExpandAllTables(pstate,
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cref->location));
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continue;
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}
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}
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}
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/* clear the exprHasAgg flag to check transform for an aggregate */
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cpstate->exprHasAgg = false;
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/* transform the item */
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te = transform_cypher_item(cpstate, item->val, NULL, expr_kind,
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item->name, false);
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target_list = lappend(target_list, te);
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/*
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* Did the transformed item contain an aggregate function? If it didn't,
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* add it to the potential group_clause. If it did, flag that we found
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* an aggregate in an expression
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*/
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if (!cpstate->exprHasAgg)
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{
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group_clause = lappend(group_clause, item->val);
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}
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else
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{
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hasAgg = true;
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}
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}
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/*
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* If we found an aggregate function, we need to return the group_clause,
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* even if NIL. parseCheckAggregates at the end of transform_cypher_return
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* will verify if it is valid.
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*/
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if (hasAgg)
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{
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*groupClause = group_clause;
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}
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return target_list;
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}
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/*
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* From PG's ExpandAllTables()
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* Transforms '*' (in the target list) into a list of targetlist entries.
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*/
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static List *ExpandAllTables(ParseState *pstate, int location)
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{
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List *target = NIL;
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bool found_table = false;
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ListCell *l;
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foreach(l, pstate->p_namespace)
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{
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ParseNamespaceItem *nsitem = (ParseNamespaceItem *) lfirst(l);
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/* Ignore table-only items */
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if (!nsitem->p_cols_visible)
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continue;
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/* Should not have any lateral-only items when parsing targetlist */
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Assert(!nsitem->p_lateral_only);
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/* Remember we found a p_cols_visible item */
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found_table = true;
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target = list_concat(target, expand_rel_attrs(pstate,
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nsitem->p_rte,
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nsitem->p_rtindex,
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0, location));
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}
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/* Check for "RETURN *;" */
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if (!found_table)
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ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
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errmsg("RETURN * without a pattern is not valid"),
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parser_errposition(pstate, location)));
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return target;
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}
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/*
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* From PG's expandRelAttrs
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* Modified to exclude hidden variables and aliases in RETURN *
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*/
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static List *expand_rel_attrs(ParseState *pstate, RangeTblEntry *rte,
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int rtindex, int sublevels_up, int location)
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{
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List *names, *vars;
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ListCell *name, *var;
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List *te_list = NIL;
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int var_prefix_len = strlen(AGE_DEFAULT_VARNAME_PREFIX);
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int alias_prefix_len = strlen(AGE_DEFAULT_ALIAS_PREFIX);
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expandRTE(rte, rtindex, sublevels_up, location, false, &names, &vars);
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/*
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* Require read access to the table. This is normally redundant with the
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* markVarForSelectPriv calls below, but not if the table has zero
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* columns.
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*/
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rte->requiredPerms |= ACL_SELECT;
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/* iterate through the variables */
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forboth(name, names, var, vars)
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{
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char *label = strVal(lfirst(name));
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Var *varnode = (Var *)lfirst(var);
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TargetEntry *te;
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/* we want to skip our "hidden" variables */
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if (strncmp(AGE_DEFAULT_VARNAME_PREFIX, label, var_prefix_len) == 0)
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continue;
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/* we want to skip out "hidden" aliases */
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if (strncmp(AGE_DEFAULT_ALIAS_PREFIX, label, alias_prefix_len) == 0)
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continue;
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/* add this variable to the list */
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te = makeTargetEntry((Expr *)varnode,
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(AttrNumber)pstate->p_next_resno++, label, false);
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te_list = lappend(te_list, te);
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/* Require read access to each column */
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markVarForSelectPriv(pstate, varnode);
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}
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Assert(name == NULL && var == NULL); /* lists not the same length? */
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return te_list;
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}
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