From 455e0a43b6ef62256a1a39707109f0be0aa8554d Mon Sep 17 00:00:00 2001
From: "zhen.song" <2438143730@qq.com>
Date: Mon, 26 Sep 2022 17:11:22 +0800
Subject: [PATCH 1/2] fix cast literal to decimal

---
 .../org/apache/calcite/rex/RexBuilder.java    | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/core/src/main/java/org/apache/calcite/rex/RexBuilder.java b/core/src/main/java/org/apache/calcite/rex/RexBuilder.java
index 4998c8daa7e..5653160a196 100644
--- a/core/src/main/java/org/apache/calcite/rex/RexBuilder.java
+++ b/core/src/main/java/org/apache/calcite/rex/RexBuilder.java
@@ -37,6 +37,7 @@
 import org.apache.calcite.sql.fun.SqlCountAggFunction;
 import org.apache.calcite.sql.fun.SqlStdOperatorTable;
 import org.apache.calcite.sql.type.ArraySqlType;
+import org.apache.calcite.sql.type.BasicSqlType;
 import org.apache.calcite.sql.type.MapSqlType;
 import org.apache.calcite.sql.type.MultisetSqlType;
 import org.apache.calcite.sql.type.SqlTypeFamily;
@@ -547,6 +548,19 @@ public RexNode makeCast(
         }
         return literal2;
       }
+      if (type instanceof BasicSqlType
+        && type.getSqlTypeName() == SqlTypeName.DECIMAL) {
+          BigDecimal newValue = null;
+          if (value instanceof BigDecimal) {
+            newValue = ((BigDecimal) value);
+          } else if (value instanceof NlsString) {
+            newValue = new BigDecimal(((NlsString) value).getValue());
+          }
+          if (newValue != null) {
+            newValue = newValue.setScale(type.getScale(), BigDecimal.ROUND_HALF_UP);
+            return makeLiteral(newValue, type, SqlTypeName.DECIMAL);
+          }
+      }
     } else if (SqlTypeUtil.isExactNumeric(type)
         && SqlTypeUtil.isInterval(exp.getType())) {
       return makeCastIntervalToExact(type, exp);
@@ -913,6 +927,11 @@ protected RexLiteral makeLiteral(
         p = 0;
       }
       o = ((TimestampString) o).round(p);
+    case DECIMAL:
+      if (o instanceof BigDecimal) {
+
+      }
+      o = ((BigDecimal) o).setScale(2, BigDecimal.ROUND_HALF_UP);
     }
     return new RexLiteral(o, type, typeName);
   }

From 6c00a0c2632d76dd5f8b15a7bfa72d862767370c Mon Sep 17 00:00:00 2001
From: "zhen.song" <2438143730@qq.com>
Date: Mon, 26 Sep 2022 17:18:26 +0800
Subject: [PATCH 2/2] add

---
 core/src/main/java/org/apache/calcite/rex/RexBuilder.java | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/core/src/main/java/org/apache/calcite/rex/RexBuilder.java b/core/src/main/java/org/apache/calcite/rex/RexBuilder.java
index 5653160a196..4eafd623478 100644
--- a/core/src/main/java/org/apache/calcite/rex/RexBuilder.java
+++ b/core/src/main/java/org/apache/calcite/rex/RexBuilder.java
@@ -927,11 +927,6 @@ protected RexLiteral makeLiteral(
         p = 0;
       }
       o = ((TimestampString) o).round(p);
-    case DECIMAL:
-      if (o instanceof BigDecimal) {
-
-      }
-      o = ((BigDecimal) o).setScale(2, BigDecimal.ROUND_HALF_UP);
     }
     return new RexLiteral(o, type, typeName);
   }