From 1fb00e99b7dc46292c095972dd60d1a2a22047d6 Mon Sep 17 00:00:00 2001
From: gwenn <gtreguier@gmail.com>
Date: Wed, 4 Mar 2020 20:26:31 +0100
Subject: [PATCH] Fix error while executing ALTER statement

`execute_bacth` should be used for DDL.
`execute` should still work except when `extra-check` feature is
activated.
---
 src/lib.rs       |  9 +++++++++
 src/statement.rs | 10 +++-------
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index dee500d..8e4ab25 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1745,5 +1745,14 @@ mod test {
             )
             .unwrap();
         }
+
+        #[test]
+        #[cfg(not(feature = "extra_check"))]
+        fn test_alter_table() {
+            let db = checked_memory_handle();
+            db.execute_batch("CREATE TABLE x(t);").unwrap();
+            // `execute_batch` should be used but `execute` should also work
+            db.execute("ALTER TABLE x RENAME TO y;", params![]).unwrap();
+        }
     }
 }
diff --git a/src/statement.rs b/src/statement.rs
index e421832..2769d6f 100644
--- a/src/statement.rs
+++ b/src/statement.rs
@@ -515,13 +515,7 @@ impl Statement<'_> {
         let r = self.stmt.step();
         self.stmt.reset();
         match r {
-            ffi::SQLITE_DONE => {
-                if self.column_count() == 0 {
-                    Ok(self.conn.changes())
-                } else {
-                    Err(Error::ExecuteReturnedResults)
-                }
-            }
+            ffi::SQLITE_DONE => Ok(self.conn.changes()),
             ffi::SQLITE_ROW => Err(Error::ExecuteReturnedResults),
             _ => Err(self.conn.decode_result(r).unwrap_err()),
         }
@@ -551,6 +545,7 @@ impl Statement<'_> {
     #[cfg(all(feature = "modern_sqlite", feature = "extra_check"))]
     #[inline]
     fn check_update(&self) -> Result<()> {
+        // sqlite3_column_count works for DML but not for DDL (ie ALTER)
         if self.column_count() > 0 || self.stmt.readonly() {
             return Err(Error::ExecuteReturnedResults);
         }
@@ -560,6 +555,7 @@ impl Statement<'_> {
     #[cfg(all(not(feature = "modern_sqlite"), feature = "extra_check"))]
     #[inline]
     fn check_update(&self) -> Result<()> {
+        // sqlite3_column_count works for DML but not for DDL (ie ALTER)
         if self.column_count() > 0 {
             return Err(Error::ExecuteReturnedResults);
         }