fix(clickhouse): support SELECT ... SETTINGS

src/main/java/net/sf/jsqlparser/parser/ParserKeywordsUtils.java

@@ -134,6 +134,7 @@ public class ParserKeywordsUtils {
             {"SELECT", RESTRICTED_ALIAS},
             {"SEMI", RESTRICTED_JSQLPARSER},
             {"SET", RESTRICTED_JSQLPARSER},
+            {"SETTINGS", RESTRICTED_JSQLPARSER},
             {"SOME", RESTRICTED_JSQLPARSER},
             {"START", RESTRICTED_JSQLPARSER},
             {"STATEMENT", RESTRICTED_JSQLPARSER},

src/main/java/net/sf/jsqlparser/statement/select/PlainSelect.java

@@ -9,13 +9,7 @@
  */
 package net.sf.jsqlparser.statement.select;
 
-import net.sf.jsqlparser.expression.Alias;
-import net.sf.jsqlparser.expression.Expression;
-import net.sf.jsqlparser.expression.OracleHierarchicalExpression;
-import net.sf.jsqlparser.expression.OracleHint;
-import net.sf.jsqlparser.expression.PreferringClause;
-import net.sf.jsqlparser.expression.WindowDefinition;
-import net.sf.jsqlparser.schema.Table;
+import static java.util.stream.Collectors.joining;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -24,8 +18,14 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
-
-import static java.util.stream.Collectors.joining;
+import net.sf.jsqlparser.expression.Alias;
+import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.expression.OracleHierarchicalExpression;
+import net.sf.jsqlparser.expression.OracleHint;
+import net.sf.jsqlparser.expression.PreferringClause;
+import net.sf.jsqlparser.expression.WindowDefinition;
+import net.sf.jsqlparser.schema.Table;
+import net.sf.jsqlparser.statement.update.UpdateSet;
 
 @SuppressWarnings({"PMD.CyclomaticComplexity"})
 public class PlainSelect extends Select {
@@ -65,6 +65,7 @@ public class PlainSelect extends Select {
     private boolean isUsingOnly = false;
     private boolean useWithNoLog = false;
     private Table intoTempTable = null;
+    private List<UpdateSet> settings = null;
 
     public PlainSelect() {}
 
@@ -323,6 +324,19 @@ public PlainSelect withIntoTempTable(Table intoTempTable) {
         return this;
     }
 
+    public List<UpdateSet> getSettings() {
+        return settings;
+    }
+
+    public void setSettings(List<UpdateSet> settings) {
+        this.settings = settings;
+    }
+
+    public PlainSelect withSettings(List<UpdateSet> settings) {
+        this.setSettings(settings);
+        return this;
+    }
+
     @Override
     public <T, S> T accept(SelectVisitor<T> selectVisitor, S context) {
         return selectVisitor.visit(this, context);
@@ -632,6 +646,11 @@ public String toString() {
         StringBuilder builder = new StringBuilder();
         super.appendTo(builder);
 
+        if (settings != null && !settings.isEmpty()) {
+            builder.append(" SETTINGS ");
+            UpdateSet.appendUpdateSetsTo(builder, settings);
+        }
+
         if (optimizeFor != null) {
             builder.append(optimizeFor);
         }
@@ -779,6 +798,18 @@ public PlainSelect addJoins(Collection<? extends Join> joins) {
         return this.withJoins(collection);
     }
 
+    public PlainSelect addSettings(UpdateSet... settings) {
+        List<UpdateSet> collection = Optional.ofNullable(getSettings()).orElseGet(ArrayList::new);
+        Collections.addAll(collection, settings);
+        return this.withSettings(collection);
+    }
+
+    public PlainSelect addSettings(Collection<? extends UpdateSet> settings) {
+        List<UpdateSet> collection = Optional.ofNullable(getSettings()).orElseGet(ArrayList::new);
+        collection.addAll(settings);
+        return this.withSettings(collection);
+    }
+
     public <E extends FromItem> E getFromItem(Class<E> type) {
         return type.cast(getFromItem());
     }

src/main/java/net/sf/jsqlparser/util/deparser/SelectDeParser.java

@@ -369,6 +369,10 @@ public <S> StringBuilder visit(PlainSelect plainSelect, S context) {
                 builder.append(" SKIP LOCKED");
             }
         }
+        if (plainSelect.getSettings() != null && !plainSelect.getSettings().isEmpty()) {
+            builder.append(" SETTINGS ");
+            deparseUpdateSets(plainSelect.getSettings(), builder, expressionVisitor);
+        }
         if (plainSelect.getOptimizeFor() != null) {
             deparseOptimizeFor(plainSelect.getOptimizeFor());
         }

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -603,6 +603,7 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_SEPARATOR:"SEPARATOR">
 |   <K_SESSION:"SESSION">
 |   <K_SET:"SET">
+|   <K_SETTINGS:"SETTINGS">
 |   <K_SETS:"SETS">
 |   <K_SHOW : "SHOW">
 |   <K_SHUTDOWN : "SHUTDOWN">
@@ -4292,6 +4293,7 @@ PlainSelect PlainSelect() #PlainSelect:
     String windowName = null;
     WindowDefinition winDef;
     Table intoTempTable = null;
+    List<UpdateSet> settings = null;
     Distinct distinct;
 }
 {
@@ -4408,6 +4410,7 @@ PlainSelect PlainSelect() #PlainSelect:
         [ LOOKAHEAD(2) (<K_NOWAIT> { plainSelect.setNoWait(true); }
                | <K_SKIP> <K_LOCKED> { plainSelect.setSkipLocked(true); }) ]
     ]
+    [ LOOKAHEAD(2) <K_SETTINGS> settings = UpdateSets() { plainSelect.setSettings(settings); } ]
     [ LOOKAHEAD(<K_OPTIMIZE>) optimize = OptimizeFor() { plainSelect.setOptimizeFor(optimize); } ]
     [ LOOKAHEAD(3) <K_INTO> <K_TEMP> intoTempTable = Table() { plainSelect.setIntoTempTable(intoTempTable);} ]
     [ LOOKAHEAD(3)<K_WITH> <K_NO> <K_LOG> { plainSelect.setUseWithNoLog(true); } ]

src/test/java/net/sf/jsqlparser/statement/select/ClickHouseTest.java

@@ -9,15 +9,15 @@
  */
 package net.sf.jsqlparser.statement.select;
 
+import static net.sf.jsqlparser.test.TestUtils.assertSqlCanBeParsedAndDeparsed;
+
 import net.sf.jsqlparser.JSQLParserException;
 import net.sf.jsqlparser.expression.Function;
 import net.sf.jsqlparser.parser.CCJSqlParserUtil;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.function.Executable;
 
-import static net.sf.jsqlparser.test.TestUtils.assertSqlCanBeParsedAndDeparsed;
-
 public class ClickHouseTest {
 
     @Test
@@ -132,4 +132,21 @@ public void testParameterizedAggregateFunctionIssue2125() throws JSQLParserExcep
         Assertions.assertEquals(1, function.getParameters().size());
         Assertions.assertEquals(1, function.getChainedParameters().size());
     }
+
+    @Test
+    public void testSettingsClauseIssue2362() throws JSQLParserException {
+        String sql = "SELECT *\nFROM events\nSETTINGS max_threads = 1";
+        PlainSelect select = (PlainSelect) assertSqlCanBeParsedAndDeparsed(sql, true);
+        Assertions.assertNotNull(select.getSettings());
+        Assertions.assertEquals(1, select.getSettings().size());
+        Assertions.assertEquals("max_threads = 1", select.getSettings().get(0).toString());
+    }
+
+    @Test
+    public void testMultipleSettingsClauseIssue2362() throws JSQLParserException {
+        String sql = "SELECT * FROM events SETTINGS max_threads = 1, max_rows_to_read = 1000";
+        PlainSelect select = (PlainSelect) assertSqlCanBeParsedAndDeparsed(sql, true);
+        Assertions.assertNotNull(select.getSettings());
+        Assertions.assertEquals(2, select.getSettings().size());
+    }
 }