parse.c

关系型数据库 Postgresql 6.5.2

			/**************************/
			/*	We are in a field now */
			/**************************/
			if (in_dot) {
				stmt->nfld--;
				strcpy(fi[stmt->nfld]->dot, fi[stmt->nfld]->name);
				strcpy(fi[stmt->nfld]->name, token);
				stmt->nfld++;
				in_dot = FALSE;

				if (delim == ',') {
					mylog("in_dot: got comma\n");
					in_field = FALSE;
				}

				continue;
			}

			if (in_as) {
				stmt->nfld--;
				strcpy(fi[stmt->nfld]->alias, token);
				mylog("alias for field '%s' is '%s'\n", fi[stmt->nfld]->name, fi[stmt->nfld]->alias);
				in_as = FALSE;
				in_field = FALSE;

				stmt->nfld++;

				if (delim == ',') {
					mylog("comma(2)\n");
				}
				continue;
			}

			/*	Function */
			if (token[0] == '(') {
				in_func = TRUE;
				blevel = 1;
				fi[stmt->nfld-1]->func = TRUE;
				/*	name will have the function name -- maybe useful some day */
				mylog("**** got function = '%s'\n", fi[stmt->nfld-1]->name);
				continue;
			}

			if (token[0] == '.') {
				in_dot = TRUE;	
				mylog("got dot\n");
				continue;
			}

			if ( ! stricmp(token, "as")) {
				in_as = TRUE;
				mylog("got AS\n");
				continue;
			}

			/*	otherwise, its probably an expression */
			in_expr = TRUE;
			fi[stmt->nfld-1]->expr = TRUE;
			fi[stmt->nfld-1]->name[0] = '\0';
			mylog("*** setting expression\n");

		}

		if (in_from) {

			if ( ! in_table) {
				if ( ! token[0])
					continue;

				if ( ! (stmt->ntab % TAB_INCR)) {
					ti = (TABLE_INFO **) realloc(ti, (stmt->ntab + TAB_INCR) * sizeof(TABLE_INFO *));
					if ( ! ti) {
						stmt->parse_status = STMT_PARSE_FATAL;
						return FALSE;
					}
					stmt->ti = ti;
				}
				ti[stmt->ntab] = (TABLE_INFO *) malloc(sizeof(TABLE_INFO));
				if (ti[stmt->ntab] == NULL) {
					stmt->parse_status = STMT_PARSE_FATAL;
					return FALSE;
				}

				ti[stmt->ntab]->alias[0] = '\0';

				strcpy(ti[stmt->ntab]->name, token);
				mylog("got table = '%s'\n", ti[stmt->ntab]->name);

				if (delim == ',') {
					mylog("more than 1 tables\n");
				}
				else {
					in_table = TRUE;
				}
				stmt->ntab++;
				continue;
			}

			strcpy(ti[stmt->ntab-1]->alias, token);
			mylog("alias for table '%s' is '%s'\n", ti[stmt->ntab-1]->name, ti[stmt->ntab-1]->alias);
			in_table = FALSE;
			if (delim == ',') {
				mylog("more than 1 tables\n");
			}
		}
	}


	/*************************************************/
	/*	Resolve any possible field names with tables */
	/*************************************************/

	parse = TRUE;

	/*	Resolve field names with tables */
	for (i = 0; i < stmt->nfld; i++) {

		if (fi[i]->func || fi[i]->expr || fi[i]->numeric) {
			fi[i]->ti = NULL;
			fi[i]->type = -1;
			parse = FALSE;
			continue;
		}

		else if (fi[i]->quote) {		/* handle as text */
			fi[i]->ti = NULL;
			fi[i]->type = PG_TYPE_TEXT;
			fi[i]->precision = 0;
			continue;
		} 

		/*	its a dot, resolve to table or alias */
		else if (fi[i]->dot[0]) {
			for (k = 0; k < stmt->ntab; k++) {
				if ( ! stricmp(ti[k]->name, fi[i]->dot)) {
					fi[i]->ti = ti[k];
					break;
				}
				else if ( ! stricmp(ti[k]->alias, fi[i]->dot)) {
					fi[i]->ti = ti[k];
					break;
				}
			}
		}
		else if (stmt->ntab == 1)
			fi[i]->ti = ti[0];
	}

	mylog("--------------------------------------------\n");
	mylog("nfld=%d, ntab=%d\n", stmt->nfld, stmt->ntab);

	for (i=0; i < stmt->nfld; i++) {
		mylog("Field %d:  expr=%d, func=%d, quote=%d, dquote=%d, numeric=%d, name='%s', alias='%s', dot='%s'\n", i, fi[i]->expr, fi[i]->func, fi[i]->quote, fi[i]->dquote, fi[i]->numeric, fi[i]->name, fi[i]->alias, fi[i]->dot);
		if (fi[i]->ti)
		mylog("     ----> table_name='%s', table_alias='%s'\n", fi[i]->ti->name, fi[i]->ti->alias);
	}

	for (i=0; i < stmt->ntab; i++) {
		mylog("Table %d: name='%s', alias='%s'\n", i, ti[i]->name, ti[i]->alias);
	}


	/******************************************************/
	/*	Now save the SQLColumns Info for the parse tables */
	/******************************************************/


	/*	Call SQLColumns for each table and store the result */
	for (i = 0; i < stmt->ntab; i++) {

		/*	See if already got it */
		char found = FALSE;
		for (k = 0; k < conn->ntables; k++) {
			if ( ! stricmp(conn->col_info[k]->name, ti[i]->name)) {
				mylog("FOUND col_info table='%s'\n", ti[i]->name);
				found = TRUE;
				break;
			}
		}
				
		if ( ! found) {

			mylog("PARSE: Getting SQLColumns for table[%d]='%s'\n", i, ti[i]->name);

			result = SQLAllocStmt( stmt->hdbc, &hcol_stmt);
			if((result != SQL_SUCCESS) && (result != SQL_SUCCESS_WITH_INFO)) {
				stmt->errormsg = "SQLAllocStmt failed in parse_statement for columns.";
				stmt->errornumber = STMT_NO_MEMORY_ERROR;
				stmt->parse_status = STMT_PARSE_FATAL;
				return FALSE;
			}

			col_stmt = (StatementClass *) hcol_stmt;
			col_stmt->internal = TRUE;

			result = SQLColumns(hcol_stmt, "", 0, "", 0, 
						ti[i]->name, (SWORD) strlen(ti[i]->name), "", 0);
		
			mylog("        Past SQLColumns\n");
			if (result == SQL_SUCCESS) {
				mylog("      Success\n");
				if ( ! (conn->ntables % COL_INCR)) {

					mylog("PARSE: Allocing col_info at ntables=%d\n", conn->ntables);

					conn->col_info = (COL_INFO **) realloc(conn->col_info, (conn->ntables + COL_INCR) * sizeof(COL_INFO *));
					if ( ! conn->col_info) {
						stmt->parse_status = STMT_PARSE_FATAL;
						return FALSE;
					}
				}

				mylog("PARSE: malloc at conn->col_info[%d]\n", conn->ntables);
				conn->col_info[conn->ntables] = (COL_INFO *) malloc(sizeof(COL_INFO));
				if ( ! conn->col_info[conn->ntables]) {
					stmt->parse_status = STMT_PARSE_FATAL;
					return FALSE;
				}

				/*	Store the table name and the SQLColumns result structure */
				strcpy(conn->col_info[conn->ntables]->name, ti[i]->name);
				conn->col_info[conn->ntables]->result = col_stmt->result;

				/*	The connection will now free the result structures, so make
					sure that the statement doesn't free it 
				*/
				col_stmt->result = NULL;

				conn->ntables++;

				SQLFreeStmt(hcol_stmt, SQL_DROP);
				mylog("Created col_info table='%s', ntables=%d\n", ti[i]->name, conn->ntables);
			}
			else {
				SQLFreeStmt(hcol_stmt, SQL_DROP);
				break;
			}
		}

		/*	Associate a table from the statement with a SQLColumn info */
		ti[i]->col_info = conn->col_info[k];
		mylog("associate col_info: i=%d, k=%d\n", i, k);
	}


	mylog("Done SQLColumns\n");

	/******************************************************/
	/*	Now resolve the fields to point to column info    */
	/******************************************************/



	for (i = 0; i < stmt->nfld;) {

		/*	Dont worry about functions or quotes */
		if (fi[i]->func || fi[i]->quote || fi[i]->numeric) {
			i++;
			continue;
		}

		/*	Stars get expanded to all fields in the table */
		else if (fi[i]->name[0] == '*') {

			char do_all_tables;
			int total_cols, old_size, need, cols;

			mylog("expanding field %d\n", i);

			total_cols = 0;	

			if (fi[i]->ti)	/*	The star represents only the qualified table */
				total_cols = QR_get_num_tuples(fi[i]->ti->col_info->result);

			else {	/*	The star represents all tables */

				/*	Calculate the total number of columns after expansion */
				for (k = 0; k < stmt->ntab; k++) {
					total_cols += QR_get_num_tuples(ti[k]->col_info->result);
				}
			}
			total_cols--;		/* makes up for the star  */

			/*	Allocate some more field pointers if necessary */
			//-------------------------------------------------------------
			old_size = (stmt->nfld / FLD_INCR * FLD_INCR + FLD_INCR);
			need = total_cols - (old_size - stmt->nfld);

			mylog("k=%d, total_cols=%d, old_size=%d, need=%d\n", k,total_cols,old_size,need);

			if (need > 0) {
				int new_size = need / FLD_INCR * FLD_INCR + FLD_INCR;
				mylog("need more cols: new_size = %d\n", new_size);
				fi = (FIELD_INFO **) realloc(fi, (old_size + new_size) * sizeof(FIELD_INFO *));
				if ( ! fi) {
					stmt->parse_status = STMT_PARSE_FATAL;
					return FALSE;
				}
			}

			//-------------------------------------------------------------
			//	copy any other fields (if there are any) up past the expansion
			for (j = stmt->nfld - 1; j > i; j--) {
				mylog("copying field %d to %d\n", j, total_cols + j);
				fi[total_cols + j] = fi[j];
			}
			mylog("done copying fields\n");

			//-------------------------------------------------------------
			//	Set the new number of fields
			stmt->nfld += total_cols;
			mylog("stmt->nfld now at %d\n", stmt->nfld);


			//-------------------------------------------------------------
			//	copy the new field info


			do_all_tables = (fi[i]->ti ? FALSE : TRUE);

			for (k = 0; k < (do_all_tables ? stmt->ntab : 1); k++) {

				TABLE_INFO *the_ti = do_all_tables ? ti[k] : fi[i]->ti;

				cols = QR_get_num_tuples(the_ti->col_info->result);

				for (n = 0; n < cols; n++) {
					mylog("creating field info: n=%d\n", n);
					// skip malloc (already did it for the Star)
					if (k > 0 || n > 0) {
						mylog("allocating field info at %d\n", n + i);
						fi[n + i] = (FIELD_INFO *) malloc( sizeof(FIELD_INFO));
						if (fi[n + i] == NULL) {
							stmt->parse_status = STMT_PARSE_FATAL;
							return FALSE;
						}
					}
					/*	Initialize the new space (or the * field) */
					memset(fi[n + i], 0, sizeof(FIELD_INFO));
					fi[n + i]->ti = the_ti;

					mylog("about to copy at %d\n", n + i);

					getColInfo(the_ti->col_info, fi[n + i], n);

					mylog("done copying\n");
				}

				i += cols;
				mylog("i now at %d\n", i);
			}

			//-------------------------------------------------------------
		}

		/*	We either know which table the field was in because it was qualified 
			with a table name or alias -OR- there was only 1 table.
		*/
		else if (fi[i]->ti) {

			if ( ! searchColInfo(fi[i]->ti->col_info, fi[i]))
				parse = FALSE;

			i++;
		}

		/*	Don't know the table -- search all tables in "from" list */
		else {
			parse = FALSE;
			for (k = 0; k < stmt->ntab; k++) {
				if ( searchColInfo(ti[k]->col_info, fi[i])) {
					fi[i]->ti = ti[k];	/* now know the table */
					parse = TRUE;
					break;
				}
			}
			i++;
		}
	}


	if ( ! parse)
		stmt->parse_status = STMT_PARSE_INCOMPLETE;
	else
		stmt->parse_status = STMT_PARSE_COMPLETE;


	mylog("done parse_statement: parse=%d, parse_status=%d\n", parse, stmt->parse_status);
	return parse;
}