From 2b24e6bb1e45363d9d27d409e0a85acd898113c5 Mon Sep 17 00:00:00 2001
From: minleejae <mmj9808@gmail.com>
Date: Thu, 24 Sep 2026 21:40:22 +0900
Subject: [PATCH] feat: model MySQL CTAS duplicate handling

Signed-off-by: minleejae <mmj9808@gmail.com>
---
 .../statement/create/table/CreateTable.java   | 17 +++++
 .../net/sf/jsqlparser/parser/JSqlParserCC.jjt | 14 +++-
 .../MySqlCreateTableDuplicatesTest.java       | 76 +++++++++++++++++++
 3 files changed, 104 insertions(+), 3 deletions(-)
 create mode 100644 src/test/java/net/sf/jsqlparser/statement/create/MySqlCreateTableDuplicatesTest.java

diff --git a/src/main/java/net/sf/jsqlparser/statement/create/table/CreateTable.java b/src/main/java/net/sf/jsqlparser/statement/create/table/CreateTable.java
index 643ce8bc4..fc8d37973 100644
--- a/src/main/java/net/sf/jsqlparser/statement/create/table/CreateTable.java
+++ b/src/main/java/net/sf/jsqlparser/statement/create/table/CreateTable.java
@@ -35,6 +35,7 @@ public class CreateTable implements Statement {
     private List<Index> indexes;
     private List<TableElement> tableElements;
     private Select select;
+    private DuplicateHandling duplicateHandling;
     private Table likeTable;
     private Table cloneTable;
     private ColDataType ofType;
@@ -50,6 +51,19 @@ public class CreateTable implements Statement {
 
     private SpannerInterleaveIn interleaveIn = null;
 
+    public enum DuplicateHandling {
+        IGNORE, REPLACE
+    }
+
+    /** MySQL's duplicate-key handling when creating a table from a query; null if omitted. */
+    public DuplicateHandling getDuplicateHandling() {
+        return duplicateHandling;
+    }
+
+    public void setDuplicateHandling(DuplicateHandling duplicateHandling) {
+        this.duplicateHandling = duplicateHandling;
+    }
+
     @Override
     public <T, S> T accept(StatementVisitor<T> statementVisitor, S context) {
         return statementVisitor.visit(this, context);
@@ -207,6 +221,9 @@ public void setUseAsKeyword(boolean useAsKeyword) {
     public StringBuilder appendSelectTo(StringBuilder builder,
             java.util.function.Consumer<Select> selectRenderer) {
         if (select != null) {
+            if (duplicateHandling != null) {
+                builder.append(' ').append(duplicateHandling);
+            }
             builder.append(useAsKeyword ? " AS " : " ");
             if (selectParenthesis) {
                 builder.append("(");
diff --git a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
index 0df99f424..463698a37 100644
--- a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
+++ b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
@@ -1440,6 +1440,11 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
         return isKeywordAhead("MATCH_RECOGNIZE") && getToken(2).kind == OPENING_BRACKET;
     }
 
+    private boolean isCreateTableQueryPrefix() {
+        int kind = getToken(1).kind;
+        return kind == K_AS || kind == K_TABLE || kind == K_IGNORE || kind == K_REPLACE;
+    }
+
     private boolean isRowPatternPrimaryAhead() {
         Token next = getToken(1);
         return next.kind == OPENING_BRACKET || next.kind == OP_CARET
@@ -15018,6 +15023,9 @@ CreateTable CreateTable(boolean isUsingOrReplace):
     [ rowMovement = RowMovement() { createTable.setRowMovement(rowMovement); }]
     [ LOOKAHEAD(2)
         { createTable.setUseAsKeyword(false); }
+        [ ( tk=<K_IGNORE> | tk=<K_REPLACE> )
+            { createTable.setDuplicateHandling(CreateTable.DuplicateHandling.valueOf(
+                    tk.image.toUpperCase(Locale.ROOT))); } ]
         [ <K_AS> { createTable.setUseAsKeyword(true); } ]
         ( LOOKAHEAD(<K_TABLE>) select=TableStatement() | select=Select() )
         { createTable.setSelect(select, false); }
@@ -15079,10 +15087,10 @@ ColumnDefinition CreateTableColumnDefinition(boolean typed):
 void CreateTableOptions(List<TableOption> options):
 { TableOption option; }
 {
-    [ LOOKAHEAD(2, { getToken(1).kind != K_AS && getToken(1).kind != K_TABLE
+    [ LOOKAHEAD(2, { !isCreateTableQueryPrefix()
             && !(getToken(1).kind == K_PARTITION && getToken(2).kind == K_BY) })
         option=CreateTableOption() { options.add(option); }
-        ( LOOKAHEAD(2, { getToken(1).kind != K_AS && getToken(1).kind != K_TABLE
+        ( LOOKAHEAD(2, { !isCreateTableQueryPrefix()
                 && !(getToken(1).kind == K_PARTITION && getToken(2).kind == K_BY)
                 && !(getToken(1).kind == K_COMMA
                     && "INTERLEAVE".equalsIgnoreCase(getToken(2).image)) })
@@ -16606,7 +16614,7 @@ TablePartitioning CreateTablePartitioning():
     ]
     [ LOOKAHEAD(2) partitionDefinitions=PartitionDefinitions()
         { partitioning.setPartitionDefinitions(partitionDefinitions); } ]
-    ( LOOKAHEAD(2, { getToken(1).kind != K_AS })
+    ( LOOKAHEAD(2, { !isCreateTableQueryPrefix() })
         parameter=CreateParameter() { partitionOptions.addAll(parameter); } )*
     {
         if (!partitionOptions.isEmpty()) {
diff --git a/src/test/java/net/sf/jsqlparser/statement/create/MySqlCreateTableDuplicatesTest.java b/src/test/java/net/sf/jsqlparser/statement/create/MySqlCreateTableDuplicatesTest.java
new file mode 100644
index 000000000..f6bdff70c
--- /dev/null
+++ b/src/test/java/net/sf/jsqlparser/statement/create/MySqlCreateTableDuplicatesTest.java
@@ -0,0 +1,76 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2026 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.statement.create;
+
+import static org.junit.jupiter.api.Assertions.*;
+import net.sf.jsqlparser.JSQLParserException;
+import net.sf.jsqlparser.parser.AbstractJSqlParser.Dialect;
+import net.sf.jsqlparser.parser.CCJSqlParserUtil;
+import net.sf.jsqlparser.statement.create.table.CreateTable;
+import net.sf.jsqlparser.statement.create.table.CreateTable.DuplicateHandling;
+import net.sf.jsqlparser.util.deparser.StatementDeParser;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+class MySqlCreateTableDuplicatesTest {
+    @ParameterizedTest
+    @ValueSource(strings = {"SELECT id FROM source", "TABLE source", "VALUES ROW(1), ROW(2)",
+            "(SELECT id FROM source)", "WITH c AS (SELECT 1 AS id) SELECT id FROM c"})
+    void retainsModifierAndSourceAfterTableOptions(String query) throws JSQLParserException {
+        for (DuplicateHandling handling : DuplicateHandling.values()) {
+            for (boolean useAs : new boolean[] {false, true}) {
+                CreateTable table = parse("CREATE TABLE t (id INT PRIMARY KEY) ENGINE=InnoDB "
+                        + handling + (useAs ? " AS " : " ") + query);
+                assertEquals(handling, table.getDuplicateHandling());
+                assertEquals(useAs, table.isUseAsKeyword());
+                assertNotNull(table.getSelect());
+                roundTrip(table);
+            }
+        }
+    }
+
+    @Test
+    void preservesPartitionAndAllowsAstMutation() throws JSQLParserException {
+        CreateTable table = parse("CREATE TABLE t (id INT PRIMARY KEY) PARTITION BY HASH(id) "
+                + "PARTITIONS 2 IGNORE AS SELECT id FROM source");
+        assertNotNull(table.getPartitioning());
+        assertNull(table.getPartitioning().getPartitionOptions());
+        table.setDuplicateHandling(DuplicateHandling.REPLACE);
+        assertTrue(table.toString().contains(" REPLACE AS SELECT"));
+        roundTrip(table);
+        table.setDuplicateHandling(null);
+        assertFalse(table.toString().contains("REPLACE"));
+        roundTrip(table);
+        assertNull(parse("CREATE TABLE t AS SELECT 1").getDuplicateHandling());
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"CREATE TABLE t IGNORE", "CREATE TABLE t REPLACE AS",
+            "CREATE TABLE t IGNORE REPLACE SELECT 1",
+            "CREATE TABLE t ENGINE=InnoDB, IGNORE SELECT 1"})
+    void rejectsMissingQueriesAndConflictingModifiers(String sql) {
+        assertThrows(JSQLParserException.class, () -> parse(sql));
+    }
+
+    private static CreateTable parse(String sql) throws JSQLParserException {
+        return (CreateTable) CCJSqlParserUtil.parse(sql, p -> p.withDialect(Dialect.MYSQL));
+    }
+
+    private static void roundTrip(CreateTable table) throws JSQLParserException {
+        StringBuilder out = new StringBuilder();
+        table.accept(new StatementDeParser(out));
+        assertEquals(table.toString(), out.toString());
+        CreateTable parsed = parse(out.toString());
+        assertEquals(table.getDuplicateHandling(), parsed.getDuplicateHandling());
+        assertEquals(table.isUseAsKeyword(), parsed.isUseAsKeyword());
+        assertEquals(out.toString(), parsed.toString());
+    }
+}