StringBuilder can be replaced with String concatenation.

In this case the usage of `StringBuilder` has no additional benefit, since it is not inside a loop where the JVM may have problems detecting String concatenation that can be optimized. The usage of "simple" String concatenation makes the code more readable and the code will be automatically optimised by the compiler.

Original pull request #1173

Author: DiegoKrupitza

spring-data-relational/src/main/java/org/springframework/data/relational/core/sql/AssignValue.java

@@ -72,7 +72,6 @@ public Expression getValue() {
 	@Override
 	public String toString() {
 
-		StringBuilder builder = new StringBuilder();
-		return builder.append(this.column).append(" = ").append(this.value).toString();
+		return this.column + " = " + this.value;
 	}
 }