/// <summary>
/// Gets the count of all rows in the table that satisfy a given condition.
/// </summary>
/// <param name="table">Name of the table whose rows are to be counted</param>
/// <param name="where">Conditional expression, such as could be placed on the end of a SQL WHERE clause</param>
/// <returns>The count of all rows in the table satisfying the condition</returns>
/// <exception cref="BadQuerySyntaxException">the SQL WHERE syntax is invalid</exception>
/// <exception cref="InstallerException">the View could not be executed</exception>
/// <exception cref="InvalidHandleException">the Database handle is invalid</exception>
public int CountRows(string table, string where)
{
if (String.IsNullOrEmpty(table))
{
throw new ArgumentNullException("table");
}
// to support temporary tables like _Streams, run the query even if the table isn't persistent
TableInfo tableInfo = this.Tables[table];
string primaryKeys = tableInfo == null ? "*" : String.Concat("`", tableInfo.PrimaryKeys[0], "`");
int count;
try
{
using (View view = this.OpenView(
"SELECT {0} FROM `{1}`{2}",
primaryKeys,
table,
(where != null && where.Length != 0 ? " WHERE " + where : "")))
{
view.Execute();
for (count = 0; ; count++)
{
// Avoid creating unnecessary Record objects by not calling View.Fetch().
int recordHandle;
uint ret = RemotableNativeMethods.MsiViewFetch((int)view.Handle, out recordHandle);
if (ret == (uint)NativeMethods.Error.NO_MORE_ITEMS)
{
break;
}
if (ret != 0)
{
throw InstallerException.ExceptionFromReturnCode(ret);
}
RemotableNativeMethods.MsiCloseHandle(recordHandle);
}
}
}
catch (BadQuerySyntaxException)
{
// table was missing
count = 0;
}
return(count);
}
/// <summary>
/// Gets the count of all rows in the table that satisfy a given condition.
/// </summary>
/// <param name="table">Name of the table whose rows are to be counted</param>
/// <param name="where">Conditional expression, such as could be placed on the end of a SQL WHERE clause</param>
/// <returns>The count of all rows in the table satisfying the condition</returns>
/// <exception cref="BadQuerySyntaxException">the SQL WHERE syntax is invalid</exception>
/// <exception cref="InstallerException">the View could not be executed</exception>
/// <exception cref="InvalidHandleException">the Database handle is invalid</exception>
public int CountRows(string table, string where)
{
if (String.IsNullOrEmpty(table))
{
throw new ArgumentNullException("table");
}
int count;
using (View view = this.OpenView(
"SELECT `{0}` FROM `{1}`{2}",
this.Tables[table].PrimaryKeys[0],
table,
(where != null && where.Length != 0 ? " WHERE " + where : "")))
{
view.Execute();
for (count = 0; ; count++)
{
// Avoid creating unnecessary Record objects by not calling View.Fetch().
int recordHandle;
uint ret = RemotableNativeMethods.MsiViewFetch((int)view.Handle, out recordHandle);
if (ret == (uint)NativeMethods.Error.NO_MORE_ITEMS)
{
break;
}
if (ret != 0)
{
throw InstallerException.ExceptionFromReturnCode(ret);
}
RemotableNativeMethods.MsiCloseHandle(recordHandle);
}
}
return(count);
}
protected override bool ReleaseHandle()
{
return(RemotableNativeMethods.MsiCloseHandle((int)this.handle) == 0);
}