improved constructors

Author: Barakudum

src/main/java/org/dynapi/squirtle/core/queries/Schema.java

@@ -10,6 +10,10 @@ public class Schema implements SqlAble {
     private final String name;
     private final Schema parent;
 
+    public Schema(String name) {
+        this(name, null);
+    }
+
     public Schema(String name, Schema parent) {
         this.name = name;
         this.parent = parent;

src/main/java/org/dynapi/squirtle/core/queries/Table.java

@@ -29,6 +29,10 @@ protected static Schema initSchema(String... names) {
     protected SqlAble for_;
     protected SqlAble forPortion;
 
+    public Table(String name) {
+        this(null, name);
+    }
+
     public Table(String alias, String name) {
         this(alias, name, null, null);
     }

src/main/java/org/dynapi/squirtle/core/terms/criterion/Field.java

@@ -17,6 +17,10 @@ public class Field extends JSON implements CriterionOperations, SqlAble {
     protected Selectable table;
     protected final String name;
 
+    public Field(String name) {
+        this(null, name);
+    }
+
     public Field(String alias, String name) {
         this(alias, name, null);
     }