From 7b001994b4fafd4e14d41215420325dd36c3327d Mon Sep 17 00:00:00 2001
From: Johan Wikman <johan.wikman@mariadb.com>
Date: Wed, 31 Oct 2018 13:47:21 +0200
Subject: [PATCH] MXS-1978 Change qc_sqlite behaviour and update test

A statement like

  SELECT ... INTO OUTFILE|DUMPFILE ...

is now classified as a QUERY_TYPE_WRITE, instead of as
QUERY_TYPE_GSYSVAR_WRITE so that it will be sent only to the
master.
---
 query_classifier/qc_sqlite/qc_sqlite.cc       | 23 ++++++++++++++++---
 .../qc_sqlite/sqlite-src-3110100/src/parse.y  | 16 +++++++++++--
 query_classifier/test/expected.sql            |  6 ++---
 3 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/query_classifier/qc_sqlite/qc_sqlite.cc b/query_classifier/qc_sqlite/qc_sqlite.cc
index 3e576ccde..57d26af4d 100644
--- a/query_classifier/qc_sqlite/qc_sqlite.cc
+++ b/query_classifier/qc_sqlite/qc_sqlite.cc
@@ -2004,9 +2004,26 @@ public:
 
         if (pSelect->pInto)
         {
-            // If there's a single variable, then it's a write.
-            // mysql embedded considers it a system var write.
-            m_type_mask = QUERY_TYPE_GSYSVAR_WRITE;
+            const ExprList* pInto = pSelect->pInto;
+            mxb_assert(pInto->nExpr >= 1);
+
+            if ((pInto->nExpr == 1)
+                && (pInto->a[0].zName)
+                && ((strcmp(pInto->a[0].zName, ":DUMPFILE:") == 0)
+                    || (strcmp(pInto->a[0].zName, ":OUTFILE:") == 0)))
+            {
+                // If there is exactly one expression that has a name that is either
+                // ":DUMPFILE:" or ":OUTFILE:" then it's a SELECT ... INTO OUTFILE|DUMPFILE
+                // and the statement needs to go to master.
+                // See in parse.y, the rule for select_into.
+                m_type_mask = QUERY_TYPE_WRITE;
+            }
+            else
+            {
+                // If there's a single variable, then it's a write.
+                // mysql embedded considers it a system var write.
+                m_type_mask = QUERY_TYPE_GSYSVAR_WRITE;
+            }
 
             // Also INTO {OUTFILE|DUMPFILE} will be typed as QUERY_TYPE_GSYSVAR_WRITE.
         }
diff --git a/query_classifier/qc_sqlite/sqlite-src-3110100/src/parse.y b/query_classifier/qc_sqlite/sqlite-src-3110100/src/parse.y
index 9310d4d38..78117c2b7 100644
--- a/query_classifier/qc_sqlite/sqlite-src-3110100/src/parse.y
+++ b/query_classifier/qc_sqlite/sqlite-src-3110100/src/parse.y
@@ -1177,8 +1177,20 @@ select_into_opt(A) ::= select_into(X). {A = X;}
 %type select_into {ExprList*}
 %destructor select_into {sqlite3ExprListDelete(pParse->db, $$);}
 select_into(A) ::= INTO variables(X). {A = X;}
-select_into(A) ::= INTO DUMPFILE STRING. {A = sqlite3ExprListAppend(pParse, 0, 0);}
-select_into(A) ::= INTO OUTFILE STRING. {A = sqlite3ExprListAppend(pParse, 0, 0);}
+// In order to allow us to distinguish between "INTO @var" and
+// "INTO OUTFILE" or "INTO DUMPFILE", we give the expression list
+// a name that cannot be a variable and look for that in
+// maxscaleCollectInfoFromSelect().
+select_into(A) ::= INTO DUMPFILE STRING. {
+    static Token dumpfile = { ":DUMPFILE:", 10 };
+    A = sqlite3ExprListAppend(pParse, 0, 0);
+    sqlite3ExprListSetName(pParse, A, &dumpfile, 1);
+}
+select_into(A) ::= INTO OUTFILE STRING. {
+    static Token outfile = { ":OUTFILE:", 9 };
+    A = sqlite3ExprListAppend(pParse, 0, 0);
+    sqlite3ExprListSetName(pParse, A, &outfile, 1);
+}
 
 %type select_options {int}
 select_options(A) ::= . {A = 0;}
diff --git a/query_classifier/test/expected.sql b/query_classifier/test/expected.sql
index 702017af5..55a350bd2 100644
--- a/query_classifier/test/expected.sql
+++ b/query_classifier/test/expected.sql
@@ -25,8 +25,6 @@ QUERY_TYPE_READ|QUERY_TYPE_WRITE
 QUERY_TYPE_READ|QUERY_TYPE_WRITE
 QUERY_TYPE_DEALLOC_PREPARE
 QUERY_TYPE_WRITE
+QUERY_TYPE_WRITE
+QUERY_TYPE_WRITE
 QUERY_TYPE_GSYSVAR_WRITE
-QUERY_TYPE_GSYSVAR_WRITE
-QUERY_TYPE_GSYSVAR_WRITE
-
-