bug fix on sqlblock and documentations

README.md

@@ -233,6 +233,28 @@ SELECT * FROM table 1 UNION ALL SELECT * FROM table 2
 ## Delete Data:
 - Use a query like `DELETE FROM <table_name> [WHERE <conditions>]` to delete rows from a table that matches the conditions.
   
+## Performance Measurement 
+- Execution time can be recorded using the `stats` command described above.
+  - `stats` command without any argument will show the execution time of all queries executed so far.
+  - `stats reset` will reset the timer for total execution time printed by `stats` command above.
+  - `stats on` will show execution time for every following query until a `stats off` command is received.
+
+## MonetDB Passthrough for Hybrid Engine 
+AQuery++ supports MonetDB passthrough for hybrid engine. Simply put standard SQL queries inside a \<sql> \</sql> block. <br>
+
+Each query inside an sql block must be separated by a semicolon. And they will be sent to MonetDB directly which means they should be written in MonetDB dialect instead of AQuery dialect. Please refer to the [MonetDB documentation](https://www.monetdb.org/documentation-Sep2022/user-guide/sql-summary/) for more information.
+
+For example:
+```
+CREATE TABLE my_table (c1 INT, c2 INT, c3 STRING)
+INSERT INTO my_table VALUES(10, 20, "example"), (20, 30, "example2")
+<sql>
+INSERT INTO my_table VALUES(10, 20, "example3");
+CREATE INDEX idx1 ON my_table(c1);
+</sql>
+SELECT * FROM my_table WHERE c1 > 10
+```
+
 ## Built-in functions: 
 - `avg[s]`: average of a column. `avgs(col), avgs(w, col)` is rolling and moving average with window `w` of the column `col`.
 - `var[s]`, `stddev[s]`: [moving/rolling] **population** variance, standard deviation.

reconstruct/ast.py

@@ -1037,6 +1037,7 @@ class insert(ast_node):
                 if isinstance(v, dict):
                     keys = v.keys()
                     v = list(v.values())
+                v = [f"'{vv}'" if type(vv) is str else vv for vv in v]
                 _vals.append(v)
             values = _vals
             
@@ -1547,7 +1548,7 @@ class passthru_sql(ast_node):
         for sql in sqls:
             sq = sql.strip(' \t\n\r;')
             if sq:
-                context.queries.append('Q' + sql + ';')
+                context.queries.append('Q' + sql.strip('\r\n\t ;') + ';')
                 lq = sq.lower()
                 if lq.startswith('select'):
                     context.queries.append('O')

server/server.cpp

@@ -207,21 +207,27 @@ void print_monetdb_results(Server* srv, const char* sep = " ", const char* end =
         uint8_t* szs = static_cast<uint8_t*>(alloca(ncols));
         std::string header_string = "";
         const char* err_msg = nullptr;
+        const size_t l_sep = strlen(sep);
+        const size_t l_end = strlen(end);
+        char* _buffer = buffer;
+
         for(uint32_t i = 0; i < ncols; ++i){
             err_msg = monetdbe_result_fetch(_res, &cols[i], i);
-            if(err_msg) { free(cols); return; }
+            if(err_msg) { goto cleanup; }
             col_data[i] = static_cast<char *>(cols[i]->data);
             prtfns[i] = monetdbe_prtfns[cols[i]->type];
             szs [i] = monetdbe_type_szs[cols[i]->type];
             header_string = header_string + cols[i]->name + sep + '|' + sep;
         }
-        const size_t l_sep = strlen(sep);
+
-        const size_t l_end = strlen(end);
+        if(l_sep > 512 || l_end > 512) {
+            puts("Error: separator or end string too long");
+            goto cleanup;
+        }
 		if (header_string.size() - l_sep - 1>= 0)
 			header_string.resize(header_string.size() - l_sep - 1);
         header_string += end + std::string(header_string.size(), '=') + end;
         fputs(header_string.c_str(), stdout);
-        char* _buffer = buffer;
         for(uint64_t i = 0; i < srv->cnt; ++i){
             for(uint32_t j = 0; j < ncols; ++j){
                 //copy the field to buf
@@ -239,8 +245,11 @@ void print_monetdb_results(Server* srv, const char* sep = " ", const char* end =
                 _buffer = buffer;
             }
         }
+        memcpy(_buffer, end, l_end);
+        _buffer += l_end;
         if (_buffer != buffer)
             fwrite(buffer, 1, _buffer - buffer, stdout);
+cleanup:        
         free(cols);
     }
 }

tests/sqlblock.a

@@ -0,0 +1,9 @@
+CREATE TABLE my_table (c1 INT, c2 INT, c3 STRING)
+INSERT INTO my_table VALUES(10, 20, "example"), (20, 30, "example2")
+<sql>
+INSERT INTO my_table VALUES(14, 24, 'example3');
+CREATE INDEX idx1 ON my_table(c1);
+SELECT * FROM my_table WHERE c1 < 15;
+
+</sql>
+SELECT * FROM my_table WHERE c1 > 15