Refactor call of PQfnumber function

joto · joto · commit 5dc24acdf876 · 2020-01-07T10:02:19.000+01:00
Refactor the last place where a PQ* function was used directly outside
pgsql.[ch]pp.
diff --git a/src/pgsql.hpp b/src/pgsql.hpp
@@ -67,6 +67,15 @@ class pg_result_t
         return std::string(get_value(row, col), get_length(row, col));
     }
 
+    /**
+     * Get the column number from the name. Returns -1 if there is no column
+     * of that name.
+     */
+    int get_column_number(std::string const& name) const noexcept
+    {
+        return PQfnumber(m_result.get(), ('"' + name + '"').c_str());
+    }
+
 private:
     struct pg_result_deleter_t
     {
diff --git a/src/table.cpp b/src/table.cpp
@@ -119,10 +119,10 @@ void table_t::start(std::string const &conninfo,
     } //appending
     else {
         //check the columns against those in the existing table
-        auto res = m_sql_conn->query(
+        auto const res = m_sql_conn->query(
             PGRES_TUPLES_OK, "SELECT * FROM {} LIMIT 0"_format(m_target->name));
         for (auto const &column : columns) {
-            if (PQfnumber(res.get(), ('"' + column.name + '"').c_str()) < 0) {
+            if (res.get_column_number(column.name) < 0) {
                 fmt::print(stderr, "Adding new column \"{}\" to \"{}\"\n",
                            column.name, m_target->name);
                 m_sql_conn->exec("ALTER TABLE {} ADD COLUMN \"{}\" {}"_format(
