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deparse.c
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deparse.c
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/*-------------------------------------------------------------------------
*
* deparse.c
* Foreign-data wrapper for remote MySQL servers
*
* Portions Copyright (c) 2012-2014, PostgreSQL Global Development Group
*
* Portions Copyright (c) 2004-2014, EnterpriseDB Corporation.
*
* IDENTIFICATION
* deparse.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "mysql_fdw.h"
#include "pgtime.h"
#include "access/heapam.h"
#include "access/htup_details.h"
#include "access/sysattr.h"
#include "access/transam.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "datatype/timestamp.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#if PG_VERSION_NUM < 120000
#include "optimizer/var.h"
#else
#include "optimizer/optimizer.h"
#endif
#include "parser/parsetree.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
#include "utils/timestamp.h"
static char *mysql_quote_identifier(const char *s, char q);
/*
* Global context for foreign_expr_walker's search of an expression tree.
*/
typedef struct foreign_glob_cxt
{
PlannerInfo *root; /* global planner state */
RelOptInfo *foreignrel; /* the foreign relation we are planning for */
} foreign_glob_cxt;
/*
* Local (per-tree-level) context for foreign_expr_walker's search.
* This is concerned with identifying collations used in the expression.
*/
typedef enum
{
FDW_COLLATE_NONE, /* expression is of a noncollatable type */
FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
FDW_COLLATE_UNSAFE /* collation derives from something else */
} FDWCollateState;
typedef struct foreign_loc_cxt
{
Oid collation; /* OID of current collation, if any */
FDWCollateState state; /* state of current collation choice */
} foreign_loc_cxt;
/*
* Context for deparseExpr
*/
typedef struct deparse_expr_cxt
{
PlannerInfo *root; /* global planner state */
RelOptInfo *foreignrel; /* the foreign relation we are planning for */
StringInfo buf; /* output buffer to append to */
List **params_list; /* exprs that will become remote Params */
} deparse_expr_cxt;
/*
* Functions to construct string representation of a node tree.
*/
static void deparseExpr(Expr *expr, deparse_expr_cxt *context);
static void mysql_deparse_var(Var *node, deparse_expr_cxt *context);
static void mysql_deparse_const(Const *node, deparse_expr_cxt *context);
static void mysql_deparse_param(Param *node, deparse_expr_cxt *context);
#if PG_VERSION_NUM < 120000
static void mysql_deparse_array_ref(ArrayRef *node, deparse_expr_cxt *context);
#else
static void mysql_deparse_array_ref(SubscriptingRef *node, deparse_expr_cxt *context);
#endif
static void mysql_deparse_func_expr(FuncExpr *node, deparse_expr_cxt *context);
static void mysql_deparse_op_expr(OpExpr *node, deparse_expr_cxt *context);
static void mysql_deparse_operator_name(StringInfo buf, Form_pg_operator opform);
static void mysql_deparse_distinct_expr(DistinctExpr *node, deparse_expr_cxt *context);
static void mysql_deparse_scalar_array_op_expr(ScalarArrayOpExpr *node,
deparse_expr_cxt *context);
static void mysql_deparse_relabel_type(RelabelType *node, deparse_expr_cxt *context);
static void mysql_deparse_bool_expr(BoolExpr *node, deparse_expr_cxt *context);
static void mysql_deparse_null_test(NullTest *node, deparse_expr_cxt *context);
static void mysql_deparse_array_expr(ArrayExpr *node, deparse_expr_cxt *context);
static void mysql_print_remote_param(int paramindex, Oid paramtype, int32 paramtypmod,
deparse_expr_cxt *context);
static void mysql_print_remote_placeholder(Oid paramtype, int32 paramtypmod,
deparse_expr_cxt *context);
static void mysql_deparse_relation(StringInfo buf, Relation rel);
static void mysql_deparse_target_list(StringInfo buf, PlannerInfo *root, Index rtindex, Relation rel,
Bitmapset *attrs_used, List **retrieved_attrs);
static void mysql_deparse_column_ref(StringInfo buf, int varno, int varattno, PlannerInfo *root);
/*
* Functions to construct string representation of a specific types.
*/
static void deparse_interval(StringInfo buf, Datum datum);
/*
* Local variables.
*/
static char *cur_opname = NULL;
/*
* Append remote name of specified foreign table to buf.
* Use value of table_name FDW option (if any) instead of relation's name.
* Similarly, schema_name FDW option overrides schema name.
*/
static void
mysql_deparse_relation(StringInfo buf, Relation rel)
{
ForeignTable *table;
const char *nspname = NULL;
const char *relname = NULL;
ListCell *lc = NULL;
/* obtain additional catalog information. */
table = GetForeignTable(RelationGetRelid(rel));
/*
* Use value of FDW options if any, instead of the name of object itself.
*/
foreach(lc, table->options)
{
DefElem *def = (DefElem *) lfirst(lc);
if (strcmp(def->defname, "dbname") == 0)
nspname = defGetString(def);
else if (strcmp(def->defname, "table_name") == 0)
relname = defGetString(def);
}
/*
* Note: we could skip printing the schema name if it's pg_catalog, but
* that doesn't seem worth the trouble.
*/
if (nspname == NULL)
nspname = get_namespace_name(RelationGetNamespace(rel));
if (relname == NULL)
relname = RelationGetRelationName(rel);
appendStringInfo(buf, "%s.%s", mysql_quote_identifier(nspname, '`'), mysql_quote_identifier(relname, '`'));
}
static char *
mysql_quote_identifier(const char *s , char q)
{
char *result = palloc(strlen(s) * 2 + 3);
char *r = result;
*r++ = q;
while (*s)
{
if (*s == q)
*r++ = *s;
*r++ = *s;
s++;
}
*r++ = q;
*r++ = '\0';
return result;
}
/*
* Deparese SELECT statment
*/
void
mysql_deparse_select(StringInfo buf,
PlannerInfo *root,
RelOptInfo *baserel,
Bitmapset *attrs_used,
char *svr_table, List **retrieved_attrs)
{
RangeTblEntry *rte = planner_rt_fetch(baserel->relid, root);
Relation rel;
/*
* Core code already has some lock on each rel being planned, so we can
* use NoLock here.
*/
rel = heap_open(rte->relid, NoLock);
appendStringInfoString(buf, "SELECT ");
mysql_deparse_target_list(buf, root, baserel->relid, rel, attrs_used, retrieved_attrs);
/*
* Construct FROM clause
*/
appendStringInfoString(buf, " FROM ");
mysql_deparse_relation(buf, rel);
heap_close(rel, NoLock);
}
/*
* deparse remote INSERT statement
*
* The statement text is appended to buf, and we also create an integer List
* of the columns being retrieved by RETURNING (if any), which is returned
* to *retrieved_attrs.
*/
void
mysql_deparse_insert(StringInfo buf, PlannerInfo *root,
Index rtindex, Relation rel,
List *targetAttrs)
{
AttrNumber pindex;
bool first;
ListCell *lc;
appendStringInfoString(buf, "INSERT INTO ");
mysql_deparse_relation(buf, rel);
if (targetAttrs)
{
appendStringInfoChar(buf, '(');
first = true;
foreach(lc, targetAttrs)
{
int attnum = lfirst_int(lc);
if (!first)
appendStringInfoString(buf, ", ");
first = false;
mysql_deparse_column_ref(buf, rtindex, attnum, root);
}
appendStringInfoString(buf, ") VALUES (");
pindex = 1;
first = true;
foreach(lc, targetAttrs)
{
if (!first)
appendStringInfoString(buf, ", ");
first = false;
appendStringInfo(buf, "?");
pindex++;
}
appendStringInfoChar(buf, ')');
}
else
appendStringInfoString(buf, " DEFAULT VALUES");
}
void
mysql_deparse_analyze(StringInfo sql, char *dbname, char *relname)
{
appendStringInfo(sql, "SELECT");
appendStringInfo(sql, " round(((data_length + index_length)), 2)");
appendStringInfo(sql, " FROM information_schema.TABLES");
appendStringInfo(sql, " WHERE table_schema = '%s' AND table_name = '%s'", dbname, relname);
}
/*
* Emit a target list that retrieves the columns specified in attrs_used.
* This is used for both SELECT and RETURNING targetlists.
*/
static void
mysql_deparse_target_list(StringInfo buf,
PlannerInfo *root,
Index rtindex,
Relation rel,
Bitmapset *attrs_used,
List **retrieved_attrs)
{
TupleDesc tupdesc = RelationGetDescr(rel);
bool have_wholerow;
bool first;
int i;
/* If there's a whole-row reference, we'll need all the columns. */
have_wholerow = bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
attrs_used);
first = true;
*retrieved_attrs = NIL;
for (i = 1; i <= tupdesc->natts; i++)
{
Form_pg_attribute attr = TupleDescAttr(tupdesc, i - 1);
/* Ignore dropped attributes. */
if (attr->attisdropped)
continue;
if (have_wholerow ||
bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
attrs_used))
{
if (!first)
appendStringInfoString(buf, ", ");
first = false;
mysql_deparse_column_ref(buf, rtindex, i, root);
*retrieved_attrs = lappend_int(*retrieved_attrs, i);
}
}
/* Don't generate bad syntax if no undropped columns */
if (first)
appendStringInfoString(buf, "NULL");
}
/*
* Deparse WHERE clauses in given list of RestrictInfos and append them to buf.
*
* baserel is the foreign table we're planning for.
*
* If no WHERE clause already exists in the buffer, is_first should be true.
*
* If params is not NULL, it receives a list of Params and other-relation Vars
* used in the clauses; these values must be transmitted to the remote server
* as parameter values.
*
* If params is NULL, we're generating the query for EXPLAIN purposes,
* so Params and other-relation Vars should be replaced by dummy values.
*/
void
mysql_append_where_clause(StringInfo buf,
PlannerInfo *root,
RelOptInfo *baserel,
List *exprs,
bool is_first,
List **params)
{
deparse_expr_cxt context;
ListCell *lc;
if (params)
*params = NIL; /* initialize result list to empty */
/* Set up context struct for recursion */
context.root = root;
context.foreignrel = baserel;
context.buf = buf;
context.params_list = params;
foreach(lc, exprs)
{
RestrictInfo *ri = (RestrictInfo *) lfirst(lc);
/* Connect expressions with "AND" and parenthesize each condition. */
if (is_first)
appendStringInfoString(buf, " WHERE ");
else
appendStringInfoString(buf, " AND ");
appendStringInfoChar(buf, '(');
deparseExpr(ri->clause, &context);
appendStringInfoChar(buf, ')');
is_first = false;
}
}
/*
* Construct name to use for given column, and emit it into buf.
* If it has a column_name FDW option, use that instead of attribute name.
*/
static void
mysql_deparse_column_ref(StringInfo buf, int varno, int varattno, PlannerInfo *root)
{
RangeTblEntry *rte;
char *colname = NULL;
List *options;
ListCell *lc;
/* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
Assert(!IS_SPECIAL_VARNO(varno));
/* Get RangeTblEntry from array in PlannerInfo. */
rte = planner_rt_fetch(varno, root);
/*
* If it's a column of a foreign table, and it has the column_name FDW
* option, use that value.
*/
options = GetForeignColumnOptions(rte->relid, varattno);
foreach(lc, options)
{
DefElem *def = (DefElem *) lfirst(lc);
if (strcmp(def->defname, "column_name") == 0)
{
colname = defGetString(def);
break;
}
}
/*
* If it's a column of a regular table or it doesn't have column_name FDW
* option, use attribute name.
*/
if (colname == NULL)
#if PG_VERSION_NUM >= 110000
colname = get_attname(rte->relid, varattno, false);
#else
colname = get_relid_attribute_name(rte->relid, varattno);
#endif
appendStringInfoString(buf, mysql_quote_identifier(colname, '`'));
}
static void
mysql_deparse_string(StringInfo buf, const char *val, bool isstr)
{
const char *valptr;
int i = -1;
for (valptr = val; *valptr; valptr++)
{
char ch = *valptr;
i++;
if (i == 0 && isstr)
appendStringInfoChar(buf, '\'');
/*
* Remove '{', '}' and \" character from the string. Because
* this syntax is not recognize by the remote MySQL server.
*/
if ((ch == '{' && i == 0) || (ch == '}' && (i == (strlen(val) - 1))) || ch == '\"')
continue;
if (ch == ',' && isstr)
{
appendStringInfoChar(buf, '\'');
appendStringInfoChar(buf, ch);
appendStringInfoChar(buf, ' ');
appendStringInfoChar(buf, '\'');
continue;
}
appendStringInfoChar(buf, ch);
}
if (isstr)
appendStringInfoChar(buf, '\'');
}
/*
* Append a SQL string literal representing "val" to buf.
*/
static void
mysql_deparse_string_literal(StringInfo buf, const char *val)
{
const char *valptr;
appendStringInfoChar(buf, '\'');
for (valptr = val; *valptr; valptr++)
{
char ch = *valptr;
if (SQL_STR_DOUBLE(ch, true))
appendStringInfoChar(buf, ch);
appendStringInfoChar(buf, ch);
}
appendStringInfoChar(buf, '\'');
}
/*
* Deparse given expression into context->buf.
*
* This function must support all the same node types that foreign_expr_walker
* accepts.
*
* Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
* scheme: anything more complex than a Var, Const, function call or cast
* should be self-parenthesized.
*/
static void
deparseExpr(Expr *node, deparse_expr_cxt *context)
{
if (node == NULL)
return;
switch (nodeTag(node))
{
case T_Var:
mysql_deparse_var((Var *) node, context);
break;
case T_Const:
mysql_deparse_const((Const *) node, context);
break;
case T_Param:
mysql_deparse_param((Param *) node, context);
break;
#if PG_VERSION_NUM < 120000
case T_ArrayRef:
mysql_deparse_array_ref((ArrayRef *) node, context);
#else
case T_SubscriptingRef:
mysql_deparse_array_ref((SubscriptingRef *) node, context);
#endif
break;
case T_FuncExpr:
mysql_deparse_func_expr((FuncExpr *) node, context);
break;
case T_OpExpr:
mysql_deparse_op_expr((OpExpr *) node, context);
break;
case T_DistinctExpr:
mysql_deparse_distinct_expr((DistinctExpr *) node, context);
break;
case T_ScalarArrayOpExpr:
mysql_deparse_scalar_array_op_expr((ScalarArrayOpExpr *) node, context);
break;
case T_RelabelType:
mysql_deparse_relabel_type((RelabelType *) node, context);
break;
case T_BoolExpr:
mysql_deparse_bool_expr((BoolExpr *) node, context);
break;
case T_NullTest:
mysql_deparse_null_test((NullTest *) node, context);
break;
case T_ArrayExpr:
mysql_deparse_array_expr((ArrayExpr *) node, context);
break;
default:
elog(ERROR, "unsupported expression type for deparse: %d",
(int) nodeTag(node));
break;
}
}
/*
* Deparse Interval type into MySQL Interval representation.
*/
static void
deparse_interval(StringInfo buf, Datum datum)
{
struct pg_tm tm;
fsec_t fsec;
bool is_first = true;
#define append_interval(expr, unit) \
do { \
if (!is_first) \
appendStringInfo(buf, " %s ", cur_opname); \
appendStringInfo(buf, "INTERVAL %d %s", expr, unit); \
is_first = false; \
} while (0)
/* Check saved opname. It could be only "+" and "-" */
Assert(cur_opname);
if (interval2tm(*DatumGetIntervalP(datum), &tm, &fsec) != 0)
elog(ERROR, "could not convert interval to tm");
if (tm.tm_year > 0)
append_interval(tm.tm_year, "YEAR");
if (tm.tm_mon > 0)
append_interval(tm.tm_mon, "MONTH");
if (tm.tm_mday > 0)
append_interval(tm.tm_mday, "DAY");
if (tm.tm_hour > 0)
append_interval(tm.tm_hour, "HOUR");
if (tm.tm_min > 0)
append_interval(tm.tm_min, "MINUTE");
if (tm.tm_sec > 0)
append_interval(tm.tm_sec, "SECOND");
if (fsec > 0)
{
if (!is_first)
appendStringInfo(buf, " %s ", cur_opname);
#ifdef HAVE_INT64_TIMESTAMP
appendStringInfo(buf, "INTERVAL %d MICROSECOND", fsec);
#else
appendStringInfo(buf, "INTERVAL %f MICROSECOND", fsec);
#endif
}
}
/*
* deparse remote UPDATE statement
*
* The statement text is appended to buf, and we also create an integer List
* of the columns being retrieved by RETURNING (if any), which is returned
* to *retrieved_attrs.
*/
void
mysql_deparse_update(StringInfo buf, PlannerInfo *root,
Index rtindex, Relation rel,
List *targetAttrs, char *attname)
{
AttrNumber pindex;
bool first;
ListCell *lc;
appendStringInfoString(buf, "UPDATE ");
mysql_deparse_relation(buf, rel);
appendStringInfoString(buf, " SET ");
pindex = 2;
first = true;
foreach(lc, targetAttrs)
{
int attnum = lfirst_int(lc);
if (attnum == 1)
continue;
if (!first)
appendStringInfoString(buf, ", ");
first = false;
mysql_deparse_column_ref(buf, rtindex, attnum, root);
appendStringInfo(buf, " = ?");
pindex++;
}
appendStringInfo(buf, " WHERE %s = ?", attname);
}
/*
* deparse remote DELETE statement
*
* The statement text is appended to buf, and we also create an integer List
* of the columns being retrieved by RETURNING (if any), which is returned
* to *retrieved_attrs.
*/
void
mysql_deparse_delete(StringInfo buf, PlannerInfo *root,
Index rtindex, Relation rel,
char *name)
{
appendStringInfoString(buf, "DELETE FROM ");
mysql_deparse_relation(buf, rel);
appendStringInfo(buf, " WHERE %s = ?", name);
}
/*
* Deparse given Var node into context->buf.
*
* If the Var belongs to the foreign relation, just print its remote name.
* Otherwise, it's effectively a Param (and will in fact be a Param at
* run time). Handle it the same way we handle plain Params --- see
* deparseParam for comments.
*/
static void
mysql_deparse_var(Var *node, deparse_expr_cxt *context)
{
StringInfo buf = context->buf;
if (node->varno == context->foreignrel->relid &&
node->varlevelsup == 0)
{
/* Var belongs to foreign table */
mysql_deparse_column_ref(buf, node->varno, node->varattno, context->root);
}
else
{
/* Treat like a Param */
if (context->params_list)
{
int pindex = 0;
ListCell *lc;
/* find its index in params_list */
foreach(lc, *context->params_list)
{
pindex++;
if (equal(node, (Node *) lfirst(lc)))
break;
}
if (lc == NULL)
{
/* not in list, so add it */
pindex++;
*context->params_list = lappend(*context->params_list, node);
}
mysql_print_remote_param(pindex, node->vartype, node->vartypmod, context);
}
else
{
mysql_print_remote_placeholder(node->vartype, node->vartypmod, context);
}
}
}
/*
* Deparse given constant value into context->buf.
*
* This function has to be kept in sync with ruleutils.c's get_const_expr.
*/
static void
mysql_deparse_const(Const *node, deparse_expr_cxt *context)
{
StringInfo buf = context->buf;
Oid typoutput;
bool typIsVarlena;
char *extval;
if (node->constisnull)
{
appendStringInfoString(buf, "NULL");
return;
}
getTypeOutputInfo(node->consttype,
&typoutput, &typIsVarlena);
switch (node->consttype)
{
case INT2OID:
case INT4OID:
case INT8OID:
case OIDOID:
case FLOAT4OID:
case FLOAT8OID:
case NUMERICOID:
{
extval = OidOutputFunctionCall(typoutput, node->constvalue);
/*
* No need to quote unless it's a special value such as 'NaN'.
* See comments in get_const_expr().
*/
if (strspn(extval, "0123456789+-eE.") == strlen(extval))
{
if (extval[0] == '+' || extval[0] == '-')
appendStringInfo(buf, "(%s)", extval);
else
appendStringInfoString(buf, extval);
}
else
appendStringInfo(buf, "'%s'", extval);
}
break;
case BITOID:
case VARBITOID:
extval = OidOutputFunctionCall(typoutput, node->constvalue);
appendStringInfo(buf, "B'%s'", extval);
break;
case BOOLOID:
extval = OidOutputFunctionCall(typoutput, node->constvalue);
if (strcmp(extval, "t") == 0)
appendStringInfoString(buf, "true");
else
appendStringInfoString(buf, "false");
break;
case INTERVALOID:
deparse_interval(buf, node->constvalue);
break;
case BYTEAOID:
/*
* the string for BYTEA always seems to be in the format "\\x##"
* where # is a hex digit, Even if the value passed in is 'hi'::bytea
* we will receive "\x6869". Making this assumption allows us to
* quickly convert postgres escaped strings to mysql ones for comparison
*/
extval = OidOutputFunctionCall(typoutput, node->constvalue);
appendStringInfo(buf, "X\'%s\'", extval + 2);
break;
default:
extval = OidOutputFunctionCall(typoutput, node->constvalue);
mysql_deparse_string_literal(buf, extval);
break;
}
}
/*
* Deparse given Param node.
*
* If we're generating the query "for real", add the Param to
* context->params_list if it's not already present, and then use its index
* in that list as the remote parameter number. During EXPLAIN, there's
* no need to identify a parameter number.
*/
static void
mysql_deparse_param(Param *node, deparse_expr_cxt *context)
{
if (context->params_list)
{
int pindex = 0;
ListCell *lc;
/* find its index in params_list */
foreach(lc, *context->params_list)
{
pindex++;
if (equal(node, (Node *) lfirst(lc)))
break;
}
if (lc == NULL)
{
/* not in list, so add it */
pindex++;
*context->params_list = lappend(*context->params_list, node);
}
mysql_print_remote_param(pindex, node->paramtype, node->paramtypmod, context);
}
else
{
mysql_print_remote_placeholder(node->paramtype, node->paramtypmod, context);
}
}
/*
* Deparse an array subscript expression.
*/
static void
#if PG_VERSION_NUM < 120000
mysql_deparse_array_ref(ArrayRef *node, deparse_expr_cxt *context)
#else
mysql_deparse_array_ref(SubscriptingRef *node, deparse_expr_cxt *context)
#endif
{
StringInfo buf = context->buf;
ListCell *lowlist_item;
ListCell *uplist_item;
/* Always parenthesize the expression. */
appendStringInfoChar(buf, '(');
/*
* Deparse referenced array expression first. If that expression includes
* a cast, we have to parenthesize to prevent the array subscript from
* being taken as typename decoration. We can avoid that in the typical
* case of subscripting a Var, but otherwise do it.
*/
if (IsA(node->refexpr, Var))
deparseExpr(node->refexpr, context);
else
{
appendStringInfoChar(buf, '(');
deparseExpr(node->refexpr, context);
appendStringInfoChar(buf, ')');
}
/* Deparse subscript expressions. */
lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
foreach(uplist_item, node->refupperindexpr)
{
appendStringInfoChar(buf, '[');
if (lowlist_item)
{
deparseExpr(lfirst(lowlist_item), context);
appendStringInfoChar(buf, ':');
lowlist_item = lnext(lowlist_item);
}
deparseExpr(lfirst(uplist_item), context);
appendStringInfoChar(buf, ']');
}
appendStringInfoChar(buf, ')');
}
/*
* This possible that name of function in PostgreSQL and
* mysql differ, so return the mysql equelent function name
*/
static char*
mysql_replace_function(char *in)
{
if (strcmp(in, "btrim") == 0)
{
return "trim";
}
return in;
}
/*
* Deparse a function call.
*/
static void
mysql_deparse_func_expr(FuncExpr *node, deparse_expr_cxt *context)
{
StringInfo buf = context->buf;
HeapTuple proctup;
Form_pg_proc procform;
const char *proname;
bool first;
ListCell *arg;
/*
* Normal function: display as proname(args).
*/
proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(node->funcid));
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", node->funcid);
procform = (Form_pg_proc) GETSTRUCT(proctup);
/* Translate PostgreSQL function into mysql function */
proname = mysql_replace_function(NameStr(procform->proname));
/* Deparse the function name ... */
appendStringInfo(buf, "%s(", proname);
/* ... and all the arguments */
first = true;
foreach(arg, node->args)
{
if (!first)
appendStringInfoString(buf, ", ");
deparseExpr((Expr *) lfirst(arg), context);
first = false;
}
appendStringInfoChar(buf, ')');
ReleaseSysCache(proctup);
}
/*
* Deparse given operator expression. To avoid problems around
* priority of operations, we always parenthesize the arguments.
*/
static void
mysql_deparse_op_expr(OpExpr *node, deparse_expr_cxt *context)
{
StringInfo buf = context->buf;
HeapTuple tuple;
Form_pg_operator form;
char oprkind;
ListCell *arg;
/* Retrieve information about the operator from system catalog. */
tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for operator %u", node->opno);
form = (Form_pg_operator) GETSTRUCT(tuple);
oprkind = form->oprkind;
/* Sanity check. */
Assert((oprkind == 'r' && list_length(node->args) == 1) ||
(oprkind == 'l' && list_length(node->args) == 1) ||
(oprkind == 'b' && list_length(node->args) == 2));
/* Always parenthesize the expression. */
appendStringInfoChar(buf, '(');
/* Deparse left operand. */
if (oprkind == 'r' || oprkind == 'b')
{
arg = list_head(node->args);
deparseExpr(lfirst(arg), context);
appendStringInfoChar(buf, ' ');
}
/* Deparse operator name. */
mysql_deparse_operator_name(buf, form);
/* Deparse right operand. */
if (oprkind == 'l' || oprkind == 'b')
{
arg = list_tail(node->args);
appendStringInfoChar(buf, ' ');
deparseExpr(lfirst(arg), context);
}
appendStringInfoChar(buf, ')');
ReleaseSysCache(tuple);
}
/*
* Print the name of an operator.
*/
static void
mysql_deparse_operator_name(StringInfo buf, Form_pg_operator opform)
{
/* opname is not a SQL identifier, so we should not quote it. */
cur_opname = NameStr(opform->oprname);
/* Print schema name only if it's not pg_catalog */
if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
{
const char *opnspname;