From b708cc15e4238ddcc551dc9c20c63b7a99a7a539 Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@gmail.com>
Date: Wed, 22 Aug 2012 18:59:22 +0200
Subject: [PATCH] [#1727] Cast VARCHAR bind values to their actual string
 length

---
 jOOQ/src/main/java/org/jooq/DataType.java     | 10 +++++++++
 .../java/org/jooq/impl/AbstractDataType.java  | 14 ++++++++++++
 jOOQ/src/main/java/org/jooq/impl/Val.java     | 22 ++++++++++++++++---
 3 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/DataType.java b/jOOQ/src/main/java/org/jooq/DataType.java
index ec419a2369..ec415f8070 100644
--- a/jOOQ/src/main/java/org/jooq/DataType.java
+++ b/jOOQ/src/main/java/org/jooq/DataType.java
@@ -139,6 +139,16 @@ public interface DataType<T> extends Serializable {
      */
     String getCastTypeName(Configuration configuration);
 
+    /**
+     * Retrieve the dialect-specific type name associated with this data type
+     * used for casting
+     * <p>
+     * This is useful for some dialects that have specialised type names for
+     * cast expressions. Other dialects require type-length binding when
+     * casting, (e.g. VARCHAR(20))
+     */
+    String getCastTypeName(Configuration configuration, int length);
+
     /**
      * Retrieve the dialect-specific type name associated with this data type
      * used for casting
diff --git a/jOOQ/src/main/java/org/jooq/impl/AbstractDataType.java b/jOOQ/src/main/java/org/jooq/impl/AbstractDataType.java
index e7e9cb52e8..37ab04a1ea 100644
--- a/jOOQ/src/main/java/org/jooq/impl/AbstractDataType.java
+++ b/jOOQ/src/main/java/org/jooq/impl/AbstractDataType.java
@@ -320,6 +320,20 @@ public abstract class AbstractDataType<T> implements DataType<T> {
         return castTypeName;
     }
 
+    @Override
+    public /* final */ String getCastTypeName(Configuration configuration, int length) {
+        String result = getCastTypeName(configuration);
+
+        if (length != 0) {
+
+            // Remove existing length information, first
+            result = result.replaceAll("\\([^\\)]*\\)", "");
+            result += "(" + length + ")";
+        }
+
+        return result;
+    }
+
     @Override
     public /* final */ String getCastTypeName(Configuration configuration, int precision, int scale) {
         String result = getCastTypeName(configuration);
diff --git a/jOOQ/src/main/java/org/jooq/impl/Val.java b/jOOQ/src/main/java/org/jooq/impl/Val.java
index 30927b3752..eca510e127 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Val.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Val.java
@@ -233,16 +233,32 @@ class Val<T> extends AbstractField<T> implements Param<T> {
             toSQL(context, getValue(), getType());
         }
 
+        // [#1727] VARCHAR types should be cast to their actual lengths
+        else if (getValue() != null && type == SQLDataType.VARCHAR) {
+
+            // Multiply by 4 to be sure that even UTF-32 collations will fit
+            // But don't use larger numbers than Derby's upper limit 32672
+            toSQLCast(context, getDataType(context), Math.min(32672, 4 * ((String) getValue()).length()));
+        }
+
         // In all other cases, the bind variable can be cast normally
         else {
             toSQLCast(context, getDataType(context), 0, 0);
         }
     }
 
-    private void toSQLCast(RenderContext context, DataType<?> type, int precision, int scale) {
-        context.sql("cast(");
+    private void toSQLCast(RenderContext context, DataType<?> type, int length) {
+        context.keyword("cast(");
         toSQL(context, getValue(), getType());
-        context.sql(" as ")
+        context.keyword(" as ")
+               .sql(type.getCastTypeName(context, length))
+               .sql(")");
+    }
+
+    private void toSQLCast(RenderContext context, DataType<?> type, int precision, int scale) {
+        context.keyword("cast(");
+        toSQL(context, getValue(), getType());
+        context.keyword(" as ")
                .sql(type.getCastTypeName(context, precision, scale))
                .sql(")");
     }