public IBuildUpdateTable <T> Where(Expression <Func <T, bool> > criteria)
{
criteria.MustNotBeNull();
_builder.EndEnumeration();
_builder.Where(criteria);
return(this);
}
public static int DeleteFrom <T>(this IAccessDb db, Expression <Func <T, bool> > criteria = null)
{
var builder = new ExpressionSqlBuilder <T>(db.Provider.BuilderHelper);
builder.WriteDelete();
if (criteria != null)
{
builder.Where(criteria);
}
return(db.ExecuteCommand(builder.ToString(), builder.Parameters.ToArray()));
}
public static long Count <T>(this DbConnection db, Expression <Func <T, bool> > criteria = null)
{
var builder = new ExpressionSqlBuilder <T>(db.GetProvider().BuilderHelper);
builder.Append("select count(*) from ").WriteTableName();
if (criteria != null)
{
builder.Where(criteria);
}
return(db.GetValue <long>(builder.ToString(), builder.Parameters.ToArray()));
}
public static int DeleteFrom <T>(this DbConnection db, Expression <Func <T, bool> > criteria = null, string schemaName = null)
{
var builder = new ExpressionSqlBuilder <T>(db.GetProvider().BuilderHelper, schemaName);
builder.WriteDelete();
if (criteria != null)
{
builder.Where(criteria);
}
return(db.Execute(builder.ToString(), builder.Parameters.ToArray()));
}
/// <summary>
/// Checks if the table has any rows with optional criteria
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="db"></param>
/// <param name="criteria"></param>
/// <returns></returns>
public static bool HasAnyRows <T>(this DbConnection db, Expression <Func <T, bool> > criteria = null)
{
var builder = new ExpressionSqlBuilder <T>(db.GetProvider().BuilderHelper);
builder
.Append("select 1 from ")
.WriteTableName()
.Append(" where exists(select * from ")
.WriteTableName();
if (criteria != null)
{
builder.Where(criteria);
}
builder.Append(")");
var r = db.GetValue <int?>(builder.ToString(), builder.Parameters.ToArray());
if (r.HasValue)
{
return(true);
}
return(false);
}