On 12/25/2010 08:34 PM, Vikram Ambrose wrote:
The first issue I had was that the parser was unable to find Tables in
the SQL statement. This was because the parser assumed that the only
possible white space around keywords was ' ' or 0x20;
[...]
The second bug was that the parser would always read past the first
"endword" if there was a JOIN just before it. Resulting in tables
being added to the list that don't exist. (eg. Artist.name, not a
table but a field). Thus in order to fix this you need to check for
endwords right away if you're parsing through JOINs.
And here is an update to the patch for a third bug.
The third bug is where the driver is unable to find functions in the SQL
query.
[...]
if ( function_flag == 1 ) {
free(statement_copy);
strcpy(curr_field,itemstore);
[...]
"itemstore" is a pointer into "statement_copy", and as such you cannot
free it before the strcpy().
The patch moves the free() after the strcpy() and the parser is now able
to correctly identify function return types.
Again, 380 tests pass, 0 fail.
By the way, Merry Christmas and a Happy New Year to everyone.
Vikram.
Index: libdbi-drivers/drivers/sqlite3/dbd_sqlite3.c
===================================================================
--- libdbi-drivers.orig/drivers/sqlite3/dbd_sqlite3.c 2010-12-25 20:11:38.603387002 -0500
+++ libdbi-drivers/drivers/sqlite3/dbd_sqlite3.c 2010-12-28 04:07:47.433387000 -0500
@@ -771,10 +771,11 @@
//printf("curr_table before getTables = %s\n",curr_table);
table_count = getTables(tables,0,statement_copy,curr_table);
//printf("curr_table after getTables = %s\n",curr_table);
+ //printf("%s\n",statement_copy);
//printf("*********TABLELIST************\n");
- // for ( counter = 0 ; counter < table_count ; counter++) {
- // //printf("%s\n",tables[counter]);
- // }
+ //for ( counter = 0 ; counter < table_count ; counter++) {
+ // printf("[%i] %s\n",counter,tables[counter]);
+ //}
// resolve our curr_field to a real column
char* token;
@@ -872,7 +873,7 @@
}
}
}
- }
+ } // if item == itemstore
else {
// we have a function here
@@ -928,7 +929,6 @@
return FIELD_TYPE_STRING;
}
if ( function_flag == 1 ) {
- free(statement_copy);
// itemstore has at least the functionname( in it
strcpy(curr_field,itemstore);
strcpy(curr_field_lower, curr_field);
@@ -937,7 +937,8 @@
*item = (char)tolower((int)*item);
item++;
}
- //printf("Field is a function - %s\n",curr_field_lower);
+ //printf("Field is a function - %s\n",curr_field_lower);
+ free(statement_copy);
if ( strstr(curr_field_lower,"avg(") ||
strstr(curr_field_lower,"sum(") ||
strstr(curr_field_lower,"total(") ||
@@ -1180,6 +1181,27 @@
return type;
}
+/* Similar to C99 strstr() except ensures that there is
+ * white space around needle. */
+char *strstr_ws(const char *haystack, const char *needle){
+ const char *c = NULL;
+ int len;
+
+ len = strlen(needle);
+
+ c = haystack;
+
+ while( (c = strstr(c,needle)) != NULL){
+ if(c == haystack) return NULL;
+ if( ( *(c-1) == ' ' || *(c-1) == '\t' || *(c-1) == '\n')
+ &&
+ ( c[len] == ' ' || c[len] == '\t' || c[len] == '\n'))
+ return (char*) c;
+ }
+
+ return NULL;
+}
+
int getTables(char** tables, int index, const char* statement, char* curr_table) {
//printf("getTables\n");
/* printf("processing %s\n",statement); */
@@ -1195,16 +1217,16 @@
char* endwords[] = {"where","group","having","union","intersect","except","order","limit"};
char* nottables[] = {"natural","left","right","full","outer","inner","cross","join","as","on"};
- if ( !(item = strstr(statement, " from ")) ) {
- if ( !(item = strstr(statement, " FROM ")) )
+ if ( !(item = strstr_ws(statement, "from")) ) {
+ if ( !(item = strstr_ws(statement, "FROM")) )
/* printf("no from clause\n"); */
return index;
}
- item += 6;
+ item += strlen("from");
while ( *item != '\0' ) {
/* printf("begin parsing at %s\n", item); */
- if ( *item == ' ' || *item == ',' ) {
+ if ( *item == ' '|| *item == '\t' || *item == ',' ) {
item++;
}
else {
@@ -1229,7 +1251,8 @@
}
else {
/* printf("actual word starting here: %s\n", item); */
- while ( *item && *item != ',' && *item != ' ' && *item != ')' && *item != ';' ) {
+ while ( *item && *item != ',' && *item != ' ' && *item != '\t'
+ && *item != ')' && *item != ';' ) {
item++;
}
char word[item-start+1];
@@ -1256,11 +1279,11 @@
/* printf("not a table: %s\n", word_lower); */
// if we encounter join or as we set
// a flag because we know what to do next
- if ( strcmp(nottables[7],word_lower) == 0 ) {
+ if ( strcmp("join",word_lower) == 0 ) {
//printf("join found\n");
join_flag = 1;
}
- if ( strcmp(nottables[8],word_lower) == 0 ) {
+ if ( strcmp("as",word_lower) == 0 ) {
//printf("as found\n");
as_flag = 1;
}
@@ -1296,7 +1319,7 @@
join_flag = 0;
int skip_flag = 1;
while ( skip_flag == 1 ) {
- if ( *item == ' ') {
+ if ( *item == ' '|| *item == '\t' ) {
item++;
}
else {
@@ -1313,7 +1336,8 @@
opens--;
}
}
- while ( *item && *item != ',' && *item != ' ' && *item != '(') {
+ while ( *item && *item != ',' && *item != ' '
+ && *item != '\t' && *item != '(') {
item++;
}
if ( *item == '\0' ) {
@@ -1335,26 +1359,32 @@
word_lower[i] = tolower(word_lower[i]);
i++;
}
- if ( strcmp(nottables[7],word_lower) == 0 ) {
+ if ( strcmp("join",word_lower) == 0 ) {
//printf("stop skip after join found\n");
// we have found the next join, stop skipping
join_flag = 1;
skip_flag = 0;
break;
}
+ for ( i = 0 ; i < (sizeof(endwords)/sizeof *(endwords)) ; i++ ) {
+ if ( strcmp(endwords[i],word_lower) == 0 ) {
+ /* printf("end word!\n"); */
+ return index;
+ }
+ }
}
}
- }
- }
- }
+ } // if join_flag
+ } // if as_flag else
+ } // if not_word_flag else
if ( *item == '\0' ) {
/* printf("returning %d",index); */
return index;
}
- item++;
- }
- }
- }
+ item++;
+ } // if *item == '(' else
+ } // if *item == ' '|| *item == '\t' || *item == ',' else
+ } // while
/* printf("returning %d\n",index); */
return index;
}
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