Merge pull request #18056 from zhangjmruc/master

Fix issue #17160 by adding show settings like '...'

src/Interpreters/InterpreterShowTablesQuery.cpp

@@ -79,6 +79,26 @@ String InterpreterShowTablesQuery::getRewrittenQuery()
         return rewritten_query.str();
     }
 
+    /// SHOW SETTINGS
+    if (query.m_settings)
+    {
+        WriteBufferFromOwnString rewritten_query;
+        rewritten_query << "SELECT name, type, value FROM system.settings";
+
+        if (query.changed)
+            rewritten_query << " WHERE changed = 1";
+
+        if (!query.like.empty())
+        {
+            rewritten_query
+                << (query.changed ? " AND name " : " WHERE name ")
+                << (query.case_insensitive_like ? "ILIKE " : "LIKE ")
+                << DB::quote << query.like;
+        }
+
+        return rewritten_query.str();
+    }
+
     if (query.temporary && !query.from.empty())
         throw Exception("The `FROM` and `TEMPORARY` cannot be used together in `SHOW TABLES`", ErrorCodes::SYNTAX_ERROR);
 

src/Parsers/ASTShowTablesQuery.cpp

@@ -55,6 +55,12 @@ void ASTShowTablesQuery::formatQueryImpl(const FormatSettings & settings, Format
         settings.ostr << (settings.hilite ? hilite_keyword : "") << "SHOW CLUSTER" << (settings.hilite ? hilite_none : "");
         settings.ostr << " " << backQuoteIfNeed(cluster_str);
     }
+    else if (m_settings)
+    {
+        settings.ostr << (settings.hilite ? hilite_keyword : "") << "SHOW " << (changed ? "CHANGED " : "") << "SETTINGS" <<
+            (settings.hilite ? hilite_none : "");
+        formatLike(settings);
+    }
     else
     {
         settings.ostr << (settings.hilite ? hilite_keyword : "") << "SHOW " << (temporary ? "TEMPORARY " : "") <<

src/Parsers/ASTShowTablesQuery.h

@@ -18,6 +18,8 @@ public:
     bool clusters{false};
     bool cluster{false};
     bool dictionaries{false};
+    bool m_settings{false};
+    bool changed{false};
     bool temporary{false};
 
     String cluster_str;

src/Parsers/ParserShowTablesQuery.cpp

@@ -24,6 +24,8 @@ bool ParserShowTablesQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expec
     ParserKeyword s_clusters("CLUSTERS");
     ParserKeyword s_cluster("CLUSTER");
     ParserKeyword s_dictionaries("DICTIONARIES");
+    ParserKeyword s_settings("SETTINGS");
+    ParserKeyword s_changed("CHANGED");
     ParserKeyword s_from("FROM");
     ParserKeyword s_in("IN");
     ParserKeyword s_not("NOT");
@@ -99,6 +101,29 @@ bool ParserShowTablesQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expec
 
         query->cluster_str = std::move(cluster_str);
     }
+    else if (bool changed = s_changed.ignore(pos); changed || s_settings.ignore(pos))
+    {
+        query->m_settings = true;
+
+        if (changed)
+        {
+            query->changed = true;
+            if (!s_settings.ignore(pos, expected))
+                return false;
+        }
+
+        /// Not expected due to "SHOW SETTINGS PROFILES"
+        if (bool insensitive = s_ilike.ignore(pos); insensitive || s_like.ignore(pos))
+        {
+            if (insensitive)
+                query->case_insensitive_like = true;
+
+            if (!like_p.parse(pos, like, expected))
+                return false;
+        }
+        else
+            return false;
+    }
     else
     {
         if (s_temporary.ignore(pos))

tests/queries/0_stateless/01293_show_settings.reference

@@ -0,0 +1,5 @@
+send_timeout	Seconds	300
+connect_timeout	Seconds	10
+connect_timeout_with_failover_ms	Milliseconds	50
+connect_timeout_with_failover_secure_ms	Milliseconds	100
+max_memory_usage	UInt64	10000000000

tests/queries/0_stateless/01293_show_settings.sql

@@ -0,0 +1,3 @@
+show settings like 'send_timeout';
+SHOW SETTINGS ILIKE '%CONNECT_timeout%';
+SHOW CHANGED SETTINGS ILIKE '%MEMORY%';