From 7cb3c68d1e0f7dd02bb664b2a3625ca1cf44f60a Mon Sep 17 00:00:00 2001
From: Johan Wikman <johan.wikman@mariadb.com>
Date: Thu, 31 Aug 2017 13:23:47 +0300
Subject: [PATCH] MXS-1380 Parse UNIONs completely

Before this change, only db2.t2 was reported as table name for a
select like

    select * from db1.t1 union select * from db2.t2

With this change, db1.t1 and db2.t2 are reported.
---
 query_classifier/qc_sqlite/qc_sqlite.c | 40 ++++++++++++++++++++------
 query_classifier/test/insert.test      |  4 ++-
 query_classifier/test/maxscale.test    |  2 ++
 query_classifier/test/select.test      | 10 ++++---
 4 files changed, 43 insertions(+), 13 deletions(-)

diff --git a/query_classifier/qc_sqlite/qc_sqlite.c b/query_classifier/qc_sqlite/qc_sqlite.c
index 1fbb4981e..ab9e84fc5 100644
--- a/query_classifier/qc_sqlite/qc_sqlite.c
+++ b/query_classifier/qc_sqlite/qc_sqlite.c
@@ -167,10 +167,18 @@ static void update_field_infos_from_idlist(QC_SQLITE_INFO* info,
                                            const IdList* pIds,
                                            uint32_t usage,
                                            const ExprList* pExclude);
-static void update_field_infos_from_select(QC_SQLITE_INFO* info,
-                                           const Select* pSelect,
-                                           uint32_t usage,
-                                           const ExprList* pExclude);
+typedef enum compound_approach
+{
+    ANALYZE_COMPOUND_SELECTS,
+    IGNORE_COMPOUND_SELECTS
+} compound_approach_t;
+static void update_field_infos_from_select_compound(QC_SQLITE_INFO* info,
+                                                    const Select* pSelect,
+                                                    uint32_t usage,
+                                                    const ExprList* pExclude,
+                                                    compound_approach_t compound_approach);
+#define update_field_infos_from_select(i, s, u, e)\
+    update_field_infos_from_select_compound(i, s, u, e, ANALYZE_COMPOUND_SELECTS)
 static void update_function_info(QC_SQLITE_INFO* info,
                                  const char* name,
                                  uint32_t usage);
@@ -1193,10 +1201,11 @@ static void update_field_infos_from_idlist(QC_SQLITE_INFO* info,
     }
 }
 
-static void update_field_infos_from_select(QC_SQLITE_INFO* info,
-                                           const Select* pSelect,
-                                           uint32_t usage,
-                                           const ExprList* pExclude)
+static void update_field_infos_from_select_compound(QC_SQLITE_INFO* info,
+                                                    const Select* pSelect,
+                                                    uint32_t usage,
+                                                    const ExprList* pExclude,
+                                                    compound_approach_t compound_approach)
 {
     if (pSelect->pSrc)
     {
@@ -1257,6 +1266,21 @@ static void update_field_infos_from_select(QC_SQLITE_INFO* info,
         update_field_infos(info, 0, pSelect->pHaving, 0, QC_TOKEN_MIDDLE, pSelect->pEList);
 #endif
     }
+
+    if (compound_approach == ANALYZE_COMPOUND_SELECTS)
+    {
+        if (((pSelect->op == TK_UNION) || (pSelect->op == TK_ALL)) && pSelect->pPrior)
+        {
+            const Select* pPrior = pSelect->pPrior;
+
+            while (pPrior)
+            {
+                update_field_infos_from_select_compound(info, pPrior, usage, pExclude,
+                                                        IGNORE_COMPOUND_SELECTS);
+                pPrior = pPrior->pPrior;
+            }
+        }
+    }
 }
 
 static void update_database_names(QC_SQLITE_INFO* info, const char* zDatabase)
diff --git a/query_classifier/test/insert.test b/query_classifier/test/insert.test
index 04a5aaa73..6bf0eb805 100644
--- a/query_classifier/test/insert.test
+++ b/query_classifier/test/insert.test
@@ -523,7 +523,9 @@ insert t1 (data) values ('letter'), (1/0);
 --disable_ps_protocol
 update t1 set data='envelope' where 1/0 or 1;
 --enable_ps_protocol
-insert t1 (data) values (default), (1/0), ('dead beef');
+#MXS qc_mysqlembedded does not return all functions
+#MXS qc_get_function_info     : ERR:  != /()
+#MXS insert t1 (data) values (default), (1/0), ('dead beef');
 --disable_info
 
 set sql_mode=default;
diff --git a/query_classifier/test/maxscale.test b/query_classifier/test/maxscale.test
index 52a10478c..960149b62 100644
--- a/query_classifier/test/maxscale.test
+++ b/query_classifier/test/maxscale.test
@@ -79,3 +79,5 @@ ROLLBACK TO id;
 RELEASE SAVEPOINT id;
 
 SELECT her FROM (SELECT @@server_id as her) as t WHERE her REGEXP '.*';
+
+select * from db1.t1 union select * from db2.t2
diff --git a/query_classifier/test/select.test b/query_classifier/test/select.test
index ae8787224..451859562 100644
--- a/query_classifier/test/select.test
+++ b/query_classifier/test/select.test
@@ -3296,10 +3296,12 @@ DROP TABLE t1,t2;
 #
 
 create table t1 (a bigint unsigned);
-insert into t1 values
-  (if(1, 9223372036854775808, 1)),
-  (case when 1 then 9223372036854775808 else 1 end),
-  (coalesce(9223372036854775808, 1));
+#MXS qc_mysqlembedded does not return all functions
+#MXS qc_get_function_info     : ERR: coalesce() != case() coalesce() if()
+#insert into t1 values
+#  (if(1, 9223372036854775808, 1)),
+#  (case when 1 then 9223372036854775808 else 1 end),
+#  (coalesce(9223372036854775808, 1));
 select * from t1;
 drop table t1;
 create table t1 select