/// <summary>
/// Use an expression visitor to select which fields to update and construct the where expression, E.g:
///
/// var ev = OrmLiteConfig.DialectProvider.ExpressionVisitor>Person<());
/// dbCmd.UpdateOnly(new Person { FirstName = "JJ" }, ev.Update(p => p.FirstName).Where(x => x.FirstName == "Jimi"));
/// UPDATE "Person" SET "FirstName" = 'JJ' WHERE ("FirstName" = 'Jimi')
///
/// What's not in the update expression doesn't get updated. No where expression updates all rows. E.g:
///
/// dbCmd.UpdateOnly(new Person { FirstName = "JJ", LastName = "Hendo" }, ev.Update(p => p.FirstName));
/// UPDATE "Person" SET "FirstName" = 'JJ'
/// </summary>
public static int UpdateOnly <T>(this IDbCommand dbCmd, T model, SqlExpressionVisitor <T> onlyFields)
{
var fieldsToUpdate = onlyFields.UpdateFields.Count == 0
? onlyFields.GetAllFields()
: onlyFields.UpdateFields;
var sql = OrmLiteConfig.DialectProvider.ToUpdateRowStatement(model, fieldsToUpdate);
if (!onlyFields.WhereExpression.IsNullOrEmpty())
{
sql += " " + onlyFields.WhereExpression;
}
return(dbCmd.ExecuteSql(sql));
}
public static int Update <T>(this IDbCommand dbCmd, T obj, SqlExpressionVisitor <T> expression)
where T : new()
{
IList <string> uf;
if (expression.UpdateFields.Count == 0)
{
uf = expression.GetAllFields();
}
else
{
uf = expression.UpdateFields;
}
string sql = OrmLiteConfig.DialectProvider.ToUpdateRowStatement(obj, uf);
if (!expression.WhereExpression.IsNullOrEmpty())
{
sql = sql + expression.WhereExpression;
}
return(dbCmd.ExecuteSql(sql));
}