Merge pull request 'Added AuthorIDs' (#25) from 20-authorids into master

Reviewed-on: #25

BlogDB.c

@@ -26,6 +26,7 @@ static int TogglePost(int postID, MYSQL* con);
 static bool IsEnabled(int postID, MYSQL* con);
 static int* PostIDs(MYSQL* con);
 static int* ActivePostIDs(MYSQL* con);
+static int* AuthorIDs(MYSQL* con);
 
 // Connects to the MariaDB database and returns the connection 
 MYSQL* conn2maria()
@@ -128,7 +129,6 @@ int EditPost(int postID, char title[], char post[], MYSQL* con)
         "SELECT * FROM blog_posts WHERE id=(%d)", 
         postID
     )) exit(1);
-
 // Query the server, if successful continue, else throw error
     if (mysql_query(con, selectQuery)) 
     {
@@ -936,6 +936,58 @@ int* ActivePostIDs(MYSQL* con)
     return arr;
 }
 
+// Returns an array of IDs for all authors, 
+// the last element in the array is set to be negative as to prevent going into unallocated data.
+// Remember to free() the returned array 
+int* AuthorIDs(MYSQL* con)
+{
+    if (con == NULL) 
+    {
+        con = conn2maria();
+    }
+
+    // Query the server, if successful continue, else throw error
+    if (mysql_query(con, "SELECT COUNT(*) FROM people"))
+    {
+        fprintf(stderr, "%s\n", mysql_error(con));
+        mysql_close(con);
+        exit(1);
+    }
+
+    // Get results
+    MYSQL_RES *result = mysql_store_result(con);
+    MYSQL_ROW row;
+    row = mysql_fetch_row(result);
+
+    int count = atoi(row[0]);
+    //printf("%d\n", count);
+
+    free(result);
+   
+    // Query the server, if successful continue, else throw error
+    if (mysql_query(con, "SELECT id FROM people")) 
+    {
+        fprintf(stderr, "%s\n", mysql_error(con));
+        mysql_close(con);
+        exit(1);
+    }
+
+    MYSQL_RES *result2 = mysql_store_result(con);
+
+    int *arr = (int *)malloc(sizeof(int) * (count + 1));
+    //printf("arr was allocated: %db of memory\n", sizeof(int) * (count + 1));
+
+    for (int i = 0; i < count; ++i) {
+        row = mysql_fetch_row(result2);
+        if (row != NULL) {
+            arr[i] = atoi(row[0]);
+        }
+    }
+
+    arr[count] = -1;
+
+    return arr;
+}
 
 // Main
 int main(int argc, char *argv[])
@@ -1000,11 +1052,11 @@ int main(int argc, char *argv[])
     // ===================================
     */
 
+    /*
     // ===================================
     // Example of using 'PostIDs()'
     // ===================================
     
-    /*
     // Generate array of IDs
     int *num = PostIDs(NULL);
 
@@ -1021,6 +1073,27 @@ int main(int argc, char *argv[])
     // ===================================
     */
 
+    /*
+    // ===================================
+    // Example of using 'PostIDs()'
+    // ===================================
+
+    // Generate array of IDs
+    int *num = AuthorIDs(NULL);
+
+    // Loop until element is negative i.e. the last
+    for (int i = 0; num[i] > 0; ++i) 
+    {
+        // Print contents on a new line
+        printf("%d\n", num[i]);
+    }
+
+    // Free the memory
+    free(num);
+    
+    // ===================================
+    */
+
 
     // Open the connection
     MYSQL *con = conn2maria();