Support BigQuery PARTITION BY expression in CREATE TABLE

BigQuery partitions by a bare expression rather than a partitioning
method: PARTITION BY d, PARTITION BY DATE(ts), PARTITION BY
RANGE_BUCKET(id, GENERATE_ARRAY(0, 100, 10)). Adds
TablePartitioning.Type.EXPRESSION, which renders the expression without
a method keyword or parentheses. The MySQL HASH/KEY/RANGE/LIST forms
keep priority.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EqinwHBKuAtPEmtXr3b5P2

Author: hayssams

src/main/java/net/sf/jsqlparser/statement/create/table/TablePartitioning.java

@@ -27,7 +27,12 @@
 public class TablePartitioning implements Serializable {
 
     public enum Type {
-        HASH, KEY, RANGE, LIST
+        HASH, KEY, RANGE, LIST,
+        /**
+         * BigQuery partitions by a bare expression, without a partitioning method keyword:
+         * {@code PARTITION BY DATE(ts)}.
+         */
+        EXPRESSION
     }
 
     private Type type;
@@ -285,6 +290,10 @@ public void appendTo(StringBuilder builder, Consumer<Expression> expressionPrint
     }
 
     private void appendMethod(StringBuilder builder, Consumer<Expression> expressionPrinter) {
+        if (type == Type.EXPRESSION) {
+            expressionPrinter.accept(expression);
+            return;
+        }
         if (linear) {
             builder.append("LINEAR ");
         }

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

@@ -14895,6 +14895,7 @@ TablePartitioning CreateTablePartitioning():
 {
     TablePartitioning partitioning = null;
     TablePartitioning subPartitioning = null;
+    Expression expression = null;
     ExpressionList<Expression> expressionList = null;
     ExpressionList<Column> columns = null;
     List<PartitionDefinition> partitionDefinitions = null;
@@ -14905,9 +14906,11 @@ TablePartitioning CreateTablePartitioning():
 {
     <K_PARTITION> <K_BY>
     (
-        partitioning=HashOrKeyPartitioning()
+        // explicit lookaheads: the method keywords win over the BigQuery
+        // bare-expression alternative below, which they share a prefix with
+        LOOKAHEAD(2) partitioning=HashOrKeyPartitioning()
         |
-        <K_RANGE> { partitioning = new TablePartitioning(TablePartitioning.Type.RANGE); }
+        LOOKAHEAD(2) <K_RANGE> { partitioning = new TablePartitioning(TablePartitioning.Type.RANGE); }
         (
             "(" expressionList=SimpleExpressionList() ")" {
                 if (expressionList.size() == 1) {
@@ -14924,7 +14927,7 @@ TablePartitioning CreateTablePartitioning():
             }
         )
         |
-        <K_LIST> { partitioning = new TablePartitioning(TablePartitioning.Type.LIST); }
+        LOOKAHEAD(2) <K_LIST> { partitioning = new TablePartitioning(TablePartitioning.Type.LIST); }
         (
             "(" expressionList=SimpleExpressionList() ")" {
                 if (expressionList.size() == 1) {
@@ -14940,6 +14943,17 @@ TablePartitioning CreateTablePartitioning():
                 partitioning.setColumns(columns);
             }
         )
+        |
+        // BigQuery partitions by a bare expression: PARTITION BY d, PARTITION BY DATE(ts),
+        // PARTITION BY RANGE_BUCKET(id, GENERATE_ARRAY(0, 100, 10))
+        LOOKAHEAD({ getToken(1).kind != K_HASH && getToken(1).kind != K_KEY
+                && getToken(1).kind != K_LINEAR && getToken(1).kind != K_RANGE
+                && getToken(1).kind != K_LIST })
+        expression=SimpleExpression()
+        {
+            partitioning = new TablePartitioning(TablePartitioning.Type.EXPRESSION);
+            partitioning.setExpression(expression);
+        }
     )
     [ LOOKAHEAD({ getToken(1).kind == K_PARTITIONS })
         <K_PARTITIONS> tk=<S_LONG> { partitioning.setPartitions(Long.valueOf(tk.image)); } ]

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

@@ -11,6 +11,8 @@
 
 import net.sf.jsqlparser.JSQLParserException;
 import net.sf.jsqlparser.expression.ArrayExpression;
+import net.sf.jsqlparser.statement.create.table.CreateTable;
+import net.sf.jsqlparser.statement.create.table.TablePartitioning;
 import net.sf.jsqlparser.test.TestUtils;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Disabled;
@@ -178,4 +180,38 @@ void testAggregateFunctionOrderByWithoutNullHandling() throws JSQLParserExceptio
         String sqlStr = "SELECT ARRAY_AGG(x ORDER BY x) FROM t";
         TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
     }
+
+    @Test
+    void testCreateTablePartitionByExpression() throws JSQLParserException {
+        String sqlStr = "CREATE TABLE ds.t (id INT64, ts TIMESTAMP) PARTITION BY DATE(ts)";
+        CreateTable createTable = (CreateTable) TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+
+        Assertions.assertEquals(TablePartitioning.Type.EXPRESSION,
+                createTable.getPartitioning().getType());
+        Assertions.assertEquals("DATE(ts)",
+                createTable.getPartitioning().getExpression().toString());
+    }
+
+    @Test
+    void testCreateTablePartitionByColumnWithOptions() throws JSQLParserException {
+        String sqlStr =
+                "CREATE TABLE ds.t (id INT64, d DATE) PARTITION BY d OPTIONS (description = 'x')";
+        TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+    }
+
+    @Test
+    void testCreateTableAsSelectPartitionByAndClusterBy() throws JSQLParserException {
+        String sqlStr = "CREATE TABLE ds.t PARTITION BY d CLUSTER BY id "
+                + "AS SELECT 1 AS id, CURRENT_DATE() AS d";
+        TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+    }
+
+    @Test
+    void testCreateTablePartitionByHashStillParses() throws JSQLParserException {
+        String sqlStr = "CREATE TABLE t (id INT) PARTITION BY HASH (id)";
+        CreateTable createTable = (CreateTable) TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+
+        Assertions.assertEquals(TablePartitioning.Type.HASH,
+                createTable.getPartitioning().getType());
+    }
 }