added better db migration support than what Subsonic provides out of the box.

Migrator.net/Migrator.Providers/ColumnPropertiesMapper.cs

@@ -0,0 +1,119 @@
+using System;
+using System.Collections.Generic;
+using Migrator.Framework;
+
+namespace Migrator.Providers
+{
+    /// <summary>
+    /// This is basically a just a helper base class
+    /// per-database implementors may want to override ColumnSql
+    /// </summary>
+    public class ColumnPropertiesMapper
+    {
+        protected Dialect dialect;
+        
+        /// <summary>The SQL type</summary>
+        protected string type;
+
+        /// <summary>The name of the column</summary>
+        protected string name;
+
+        /// <summary>
+        /// the type of the column
+        /// </summary>
+        protected string columnSql;
+
+        /// <summary>
+        /// Sql if This column is Indexed
+        /// </summary>
+        protected bool indexed = false;
+
+        /// <summary>
+        /// Sql if this column has a default value
+        /// </summary>
+        protected object defaultVal;
+
+        public ColumnPropertiesMapper(Dialect dialect, string type)
+        {
+            this.dialect = dialect;
+            this.type = type;
+        }
+
+        /// <summary>
+        /// The sql for this column, override in database-specific implementation classes
+        /// </summary>
+        public virtual string ColumnSql
+        {
+            get { return columnSql; }
+        }
+
+        public string Name
+        {
+            get { return name; }
+            set { name = value; }
+        }
+        
+        public object Default
+        {
+             get { return defaultVal; }
+             set { defaultVal = value; }
+         }
+
+        public string QuotedName
+        {
+            get { return dialect.Quote(Name); }
+        }
+
+        public string IndexSql
+        {
+            get
+            {
+                if (dialect.SupportsIndex && indexed)
+                    return String.Format("INDEX({0})", dialect.Quote(name));
+                return null;
+            }
+        }
+
+        public void MapColumnProperties(Column column)
+        {
+            Name = column.Name;
+            indexed = PropertySelected(column.ColumnProperty, ColumnProperty.Indexed);
+            
+            List<string> vals = new List<string>();
+            vals.Add(dialect.ColumnNameNeedsQuote ? QuotedName : Name);
+            
+            vals.Add(type);
+            
+            if (! dialect.IdentityNeedsType)
+                AddValueIfSelected(column, ColumnProperty.Identity, vals);
+                
+            AddValueIfSelected(column, ColumnProperty.Unsigned, vals);
+            if (! PropertySelected(column.ColumnProperty, ColumnProperty.PrimaryKey) || dialect.NeedsNotNullForIdentity)
+                AddValueIfSelected(column, ColumnProperty.NotNull, vals);
+                
+            AddValueIfSelected(column, ColumnProperty.PrimaryKey, vals);
+            
+            if (dialect.IdentityNeedsType)
+                AddValueIfSelected(column, ColumnProperty.Identity, vals);
+            
+            AddValueIfSelected(column, ColumnProperty.Unique, vals);
+            AddValueIfSelected(column, ColumnProperty.ForeignKey, vals);
+
+            if (column.DefaultValue != null)
+                vals.Add(dialect.Default(column.DefaultValue));
+
+            columnSql = String.Join(" ", vals.ToArray());
+        }
+
+        private void AddValueIfSelected(Column column, ColumnProperty property, ICollection<string> vals)
+        {
+            if (PropertySelected(column.ColumnProperty, property))
+                vals.Add(dialect.SqlForProperty(property));
+        }
+
+        public static bool PropertySelected(ColumnProperty source, ColumnProperty comparison)
+        {
+            return (source & comparison) == comparison;
+        }
+    }
+}