Remove DBBrowserDB::tableColumns() method

Remove the DBBrowserDB::tableColumns() method which queries the database
for the column names of a given table and which is used for the SQL
export only. This function isn't needed at all because it generates a
whole bunch of queries for data which is already hold in memory...

src/sqlitedb.cpp

@@ -428,7 +428,7 @@ bool DBBrowserDB::dump(const QString& filename,
                 continue;
 
             // get columns
-            QStringList cols(tableColumns(it->getTableName()));
+            QStringList cols(it->table.fieldNames());
 
             QString sQuery = QString("SELECT * FROM `%1`;").arg(it->getTableName());
             QByteArray utf8Query = sQuery.toUtf8();
@@ -1237,16 +1237,3 @@ bool DBBrowserDB::loadExtension(const QString& filename)
         return false;
     }
 }
-
-QStringList DBBrowserDB::tableColumns(const QString & tableName) {
-    QStringList cols;
-    sqlite3_stmt* stmt = NULL;
-    QString q(QString("PRAGMA table_info('%1');").arg(tableName));
-    int rc = sqlite3_prepare_v2(this->_db, q.toUtf8(), q.toUtf8().length(), &stmt, NULL);
-    if (rc == SQLITE_OK) {
-        while (sqlite3_step(stmt) == SQLITE_ROW)
-            cols.push_back(QString((const char*)sqlite3_column_text(stmt, 1)));
-        sqlite3_finalize(stmt);
-    }
-    return cols;
-}

src/sqlitedb.h

@@ -58,8 +58,6 @@ public:
     bool executeSQL ( const QString & statement, bool dirtyDB=true, bool logsql=true);
     bool executeMultiSQL(const QString& statement, bool dirty = true, bool log = false);
 
-    QStringList tableColumns(const QString& tableName);
-
     /**
      * @brief getRow Executes a sqlite statement to get the rowdata(columns)
      *        for the given rowid.