From 91e9984efa944ac7a2168d35eb4ba1e9266d0b50 Mon Sep 17 00:00:00 2001
From: xiaohei <1597226206@qq.com>
Date: Sat, 20 Jul 2024 11:51:34 +0800
Subject: [PATCH] [CALCITE-6482] OracleSqlDialect support bool literal as
 predicate

---
 .../org/apache/calcite/sql/SqlDialect.java    |  7 +++++++
 .../org/apache/calcite/sql/SqlLiteral.java    |  3 +--
 .../calcite/sql/dialect/OracleSqlDialect.java | 15 +++++++++++++
 .../rel/rel2sql/RelToSqlConverterTest.java    | 21 +++++++++++++++++++
 4 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/core/src/main/java/org/apache/calcite/sql/SqlDialect.java b/core/src/main/java/org/apache/calcite/sql/SqlDialect.java
index b8877fdaf4d4..b51b564e52be 100644
--- a/core/src/main/java/org/apache/calcite/sql/SqlDialect.java
+++ b/core/src/main/java/org/apache/calcite/sql/SqlDialect.java
@@ -466,6 +466,13 @@ public void unparseCall(SqlWriter writer, SqlCall call, int leftPrec,
     }
   }
 
+  public void unparseBoolLiteral(SqlWriter writer,
+      SqlLiteral literal, int leftPrec, int rightPrec) {
+    Object value = literal.getValue();
+    writer.keyword(
+        !(value instanceof Boolean) ? "UNKNOWN" : (Boolean) value ? "TRUE" : "FALSE");
+  }
+
   public void unparseDateTimeLiteral(SqlWriter writer,
       SqlAbstractDateTimeLiteral literal, int leftPrec, int rightPrec) {
     writer.literal(literal.toString());
diff --git a/core/src/main/java/org/apache/calcite/sql/SqlLiteral.java b/core/src/main/java/org/apache/calcite/sql/SqlLiteral.java
index ae41cbe54e96..272c0d135c62 100644
--- a/core/src/main/java/org/apache/calcite/sql/SqlLiteral.java
+++ b/core/src/main/java/org/apache/calcite/sql/SqlLiteral.java
@@ -754,8 +754,7 @@ public String getStringValue() {
       int rightPrec) {
     switch (typeName) {
     case BOOLEAN:
-      writer.keyword(
-          value == null ? "UNKNOWN" : (Boolean) value ? "TRUE" : "FALSE");
+      writer.getDialect().unparseBoolLiteral(writer, this, leftPrec, rightPrec);
       break;
     case NULL:
       writer.keyword("NULL");
diff --git a/core/src/main/java/org/apache/calcite/sql/dialect/OracleSqlDialect.java b/core/src/main/java/org/apache/calcite/sql/dialect/OracleSqlDialect.java
index e99ab2a44fc2..4314438d6cb1 100644
--- a/core/src/main/java/org/apache/calcite/sql/dialect/OracleSqlDialect.java
+++ b/core/src/main/java/org/apache/calcite/sql/dialect/OracleSqlDialect.java
@@ -126,6 +126,21 @@ public OracleSqlDialect(Context context) {
     return false;
   }
 
+  @Override public void unparseBoolLiteral(SqlWriter writer,
+      SqlLiteral literal, int leftPrec, int rightPrec) {
+    Boolean value = (Boolean) literal.getValue();
+    if (value == null || majorVersion >= 23) {
+      super.unparseBoolLiteral(writer, literal, leftPrec, rightPrec);
+      return;
+    }
+    // low version oracle not support bool literal
+    final SqlWriter.Frame frame = writer.startList("(", ")");
+    writer.literal("1");
+    writer.sep(SqlStdOperatorTable.EQUALS.getName());
+    writer.literal(value ? "1" : "0");
+    writer.endList(frame);
+  }
+
   @Override public void unparseDateTimeLiteral(SqlWriter writer,
       SqlAbstractDateTimeLiteral literal, int leftPrec, int rightPrec) {
     if (literal instanceof SqlTimestampLiteral) {
diff --git a/core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java b/core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java
index 7d59542b73c4..03916bf7e94a 100644
--- a/core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java
+++ b/core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java
@@ -7700,6 +7700,27 @@ private void checkLiteral2(String expression, String expected) {
         .withOracle(11).throws_("Lower Oracle version(<12) doesn't support offset/fetch syntax!");
   }
 
+  /** Test case for
+   * <a href="https://issues.apache.org/jira/browse/CALCITE-6482">[CALCITE-6482]
+   * Oracle dialect convert bool literal when version < 23</a>.*/
+  @Test void testBoolLiteralOracle() {
+    String query = "SELECT \"e1\".\"department_id\" "
+        + "FROM \"employee\" \"e1\""
+        + "LEFT JOIN \"employee\" \"e2\""
+        + "ON TRUE";
+    String expectedVersionLow = "SELECT \"employee\".\"department_id\"\n"
+        + "FROM \"foodmart\".\"employee\"\n"
+        + "LEFT JOIN \"foodmart\".\"employee\" \"employee0\" "
+        + "ON (1 = 1)";
+    String expectedVersionHigh = "SELECT \"employee\".\"department_id\"\n"
+        + "FROM \"foodmart\".\"employee\"\n"
+        + "LEFT JOIN \"foodmart\".\"employee\" \"employee0\" "
+        + "ON TRUE";
+    sql(query)
+        .withOracle(23).ok(expectedVersionHigh)
+        .withOracle(11).ok(expectedVersionLow);
+  }
+
   /** Test case for
    * <a href="https://issues.apache.org/jira/browse/CALCITE-5265">[CALCITE-5265]
    * JDBC adapter sometimes adds unnecessary parentheses around SELECT in INSERT</a>. */