/// <summary>
/// Execute the command and return the first column of the first row of the resultset
/// (if present), or null if no resultset was returned.
/// </summary>
/// <returns>The first column of the first row of the first resultset from the query</returns>
public override object ExecuteScalar()
{
InitializeForReader();
int x = 0;
object ret = null;
SQLiteType typ = new SQLiteType();
SQLiteStatement stmt;
// We step through every statement in the command, but only grab the first row of the first resultset.
// We keep going even after obtaining it.
for (;;)
{
stmt = GetStatement(x);
x++;
if (stmt == null)
{
break;
}
if (_cnn._sql.Step(stmt) == true && ret == null)
{
ret = _cnn._sql.GetValue(stmt, 0, ref typ);
}
_cnn._sql.Reset(stmt);
}
return(ret);
}
/// <summary>
/// Retrieves the SQLiteType for a given column, and caches it to avoid repetetive interop calls.
/// </summary>
/// <param name="i">The index of the column to retrieve</param>
/// <returns>A SQLiteType structure</returns>
private SQLiteType GetSQLiteType(int i)
{
SQLiteType typ;
// Initialize the field types array if not already initialized
if (_fieldTypeArray == null)
{
_fieldTypeArray = new SQLiteType[VisibleFieldCount];
}
// Initialize this column's field type instance
if (_fieldTypeArray[i] == null)
{
_fieldTypeArray[i] = new SQLiteType();
}
typ = _fieldTypeArray[i];
// If not initialized, then fetch the declared column datatype and attempt to convert it
// to a known DbType.
if (typ.Affinity == TypeAffinity.Uninitialized)
{
typ.Type = SQLiteConvert.TypeNameToDbType(_activeStatement._sql.ColumnType(_activeStatement, i, out typ.Affinity));
}
else
{
typ.Affinity = _activeStatement._sql.ColumnAffinity(_activeStatement, i);
}
return(typ);
}
internal static Type SQLiteTypeToType(SQLiteType t)
{
if (t.Type == DbType.Object)
{
return(_affinitytotype[(int)t.Affinity]);
}
return(DbTypeToType(t.Type));
}
/// <summary>
/// Retrieves the column as an object corresponding to the underlying datatype of the column
/// </summary>
/// <param name="i">The index of the column to retrieve</param>
/// <returns>object</returns>
public override object GetValue(int i)
{
CheckClosed();
SQLiteType typ = GetSQLiteType(i);
return(_activeStatement._sql.GetValue(_activeStatement, i, ref typ));
}
/// <summary>
/// Converts a SQLiteType to a .NET Type object
/// </summary>
/// <param name="t">The SQLiteType to convert</param>
/// <returns>Returns a .NET Type object</returns>
internal static Type SQLiteTypeToType(SQLiteType t)
{
if (t.Type != DbType.Object)
{
return(SQLiteConvert.DbTypeToType(t.Type));
}
return(_typeaffinities[(int)t.Affinity]);
}
public override object GetValue(int i)
{
if ((i >= this.VisibleFieldCount) && (this._keyInfo != null))
{
return(this._keyInfo.GetValue(i - this.VisibleFieldCount));
}
SQLiteType sQLiteType = this.GetSQLiteType(i);
return(this._activeStatement._sql.GetValue(this._activeStatement, i, sQLiteType));
}
/// <summary>
/// Retrieves the column as an object corresponding to the underlying datatype of the column
/// </summary>
/// <param name="i">The index of the column to retrieve</param>
/// <returns>object</returns>
public override object GetValue(int i)
{
if (i >= VisibleFieldCount && _keyInfo != null)
{
return(_keyInfo.GetValue(i - VisibleFieldCount));
}
SQLiteType typ = GetSQLiteType(i);
return(_activeStatement._sql.GetValue(_activeStatement, i, typ));
}
/// <summary>
/// Retrieves the name of the back-end datatype of the column
/// </summary>
/// <param name="i">The index of the column to retrieve</param>
/// <returns>string</returns>
public override string GetDataTypeName(int i)
{
CheckClosed();
SQLiteType typ = GetSQLiteType(i);
if (typ.Type == DbType.Object)
{
return(SQLiteConvert.SQLiteTypeToType(typ).Name);
}
return(_activeStatement._sql.ColumnType(_activeStatement, i, out typ.Affinity));
}
public override string GetDataTypeName(int i)
{
if ((i >= this.VisibleFieldCount) && (this._keyInfo != null))
{
return(this._keyInfo.GetDataTypeName(i - this.VisibleFieldCount));
}
SQLiteType sQLiteType = this.GetSQLiteType(i);
if (sQLiteType.Type == DbType.Object)
{
return(SQLiteConvert.SQLiteTypeToType(sQLiteType).Name);
}
return(this._activeStatement._sql.ColumnType(this._activeStatement, i, out sQLiteType.Affinity));
}
internal override object GetValue(SQLiteStatement stmt, int index, SQLiteType typ)
{
if (this.IsNull(stmt, index))
{
return(DBNull.Value);
}
TypeAffinity affinity = typ.Affinity;
Type type = null;
if (typ.Type != DbType.Object)
{
type = SQLiteConvert.SQLiteTypeToType(typ);
affinity = SQLiteConvert.TypeToAffinity(type);
}
switch (affinity)
{
case TypeAffinity.Int64:
if (type != null)
{
return(Convert.ChangeType(this.GetInt64(stmt, index), type, null));
}
return(this.GetInt64(stmt, index));
case TypeAffinity.Double:
if (type != null)
{
return(Convert.ChangeType(this.GetDouble(stmt, index), type, null));
}
return(this.GetDouble(stmt, index));
case TypeAffinity.Blob:
if ((typ.Type != DbType.Guid) || (typ.Affinity != TypeAffinity.Text))
{
int nLength = (int)this.GetBytes(stmt, index, 0, null, 0, 0);
byte[] bDest = new byte[nLength];
this.GetBytes(stmt, index, 0, bDest, 0, nLength);
if ((typ.Type == DbType.Guid) && (nLength == 0x10))
{
return(new Guid(bDest));
}
return(bDest);
}
return(new Guid(this.GetText(stmt, index)));
case TypeAffinity.DateTime:
return(this.GetDateTime(stmt, index));
}
return(this.GetText(stmt, index));
}
/// <summary>
/// Retrieves the name of the back-end datatype of the column
/// </summary>
/// <param name="i">The index of the column to retrieve</param>
/// <returns>string</returns>
public override string GetDataTypeName(int i)
{
if (i >= VisibleFieldCount && _keyInfo != null)
{
return(_keyInfo.GetDataTypeName(i - VisibleFieldCount));
}
SQLiteType typ = GetSQLiteType(i);
if (typ.Type == DbType.Object)
{
return(SQLiteConvert.SQLiteTypeToType(typ).Name);
}
return(_activeStatement._sql.ColumnType(_activeStatement, i, out typ.Affinity));
}
/// <summary>
/// Helper function to retrieve a column of data from an active statement.
/// </summary>
/// <param name="stmt">The statement being step()'d through</param>
/// <param name="index">The column index to retrieve</param>
/// <param name="typ">The type of data contained in the column. If Uninitialized, this function will retrieve the datatype information.</param>
/// <returns>Returns the data in the column</returns>
internal virtual object GetValue(SQLiteStatement stmt, int index, ref SQLiteType typ)
{
if (typ.Affinity == 0)
{
typ = SQLiteConvert.ColumnToType(stmt, index);
}
if (IsNull(stmt, index))
{
return(DBNull.Value);
}
Type t = SQLiteConvert.SQLiteTypeToType(typ);
switch (TypeToAffinity(t))
{
case TypeAffinity.Blob:
if (typ.Type == DbType.Guid && typ.Affinity == TypeAffinity.Text)
{
return(new Guid(GetText(stmt, index)));
}
int n = (int)GetBytes(stmt, index, 0, null, 0, 0);
byte[] b = new byte[n];
GetBytes(stmt, index, 0, b, 0, n);
if (typ.Type == DbType.Guid && n == 16)
{
return(new Guid(b));
}
return(b);
case TypeAffinity.DateTime:
return(GetDateTime(stmt, index));
case TypeAffinity.Double:
return(Convert.ChangeType(GetDouble(stmt, index), t, null));
case TypeAffinity.Int64:
return(Convert.ChangeType(GetInt64(stmt, index), t, null));
default:
return(GetText(stmt, index));
}
}
private SQLiteType GetSQLiteType(int i)
{
if (this._fieldTypeArray == null)
{
this._fieldTypeArray = new SQLiteType[this.VisibleFieldCount];
}
if (this._fieldTypeArray[i] == null)
{
this._fieldTypeArray[i] = new SQLiteType();
}
SQLiteType type = this._fieldTypeArray[i];
if (type.Affinity == TypeAffinity.Uninitialized)
{
type.Type = SQLiteConvert.TypeNameToDbType(this._activeStatement._sql.ColumnType(this._activeStatement, i, out type.Affinity));
return(type);
}
type.Affinity = this._activeStatement._sql.ColumnAffinity(this._activeStatement, i);
return(type);
}
/// <summary>
/// Execute the command and return the first column of the first row of the resultset
/// (if present), or null if no resultset was returned.
/// </summary>
/// <returns>The first column of the first row of the first resultset from the query</returns>
public override object ExecuteScalar()
{
InitializeForReader();
int x = 0;
object ret = null;
SQLiteType typ = new SQLiteType();
SQLiteStatement stmt;
// We step through every statement in the command, but only grab the first row of the first resultset.
// We keep going even after obtaining it.
for (;;)
{
stmt = GetStatement(x);
x++;
if (stmt == null) break;
if (_cnn._sql.Step(stmt) == true && ret == null)
{
ret = _cnn._sql.GetValue(stmt, 0, ref typ);
}
_cnn._sql.Reset(stmt);
}
return ret;
}
/// <summary>
/// Helper function to retrieve a column of data from an active statement.
/// </summary>
/// <param name="stmt">The statement being step()'d through</param>
/// <param name="flags">The flags associated with the connection.</param>
/// <param name="index">The column index to retrieve</param>
/// <param name="typ">The type of data contained in the column. If Uninitialized, this function will retrieve the datatype information.</param>
/// <returns>Returns the data in the column</returns>
internal override object GetValue(SQLiteStatement stmt, SQLiteConnectionFlags flags, int index, SQLiteType typ)
{
TypeAffinity aff = typ.Affinity;
if (aff == TypeAffinity.Null) return DBNull.Value;
Type t = null;
if (typ.Type != DbType.Object)
{
t = SQLiteConvert.SQLiteTypeToType(typ);
aff = TypeToAffinity(t);
}
if ((flags & SQLiteConnectionFlags.GetAllAsText) == SQLiteConnectionFlags.GetAllAsText)
return GetText(stmt, index);
switch (aff)
{
case TypeAffinity.Blob:
if (typ.Type == DbType.Guid && typ.Affinity == TypeAffinity.Text)
return new Guid(GetText(stmt, index));
int n = (int)GetBytes(stmt, index, 0, null, 0, 0);
byte[] b = new byte[n];
GetBytes(stmt, index, 0, b, 0, n);
if (typ.Type == DbType.Guid && n == 16)
return new Guid(b);
return b;
case TypeAffinity.DateTime:
return GetDateTime(stmt, index);
case TypeAffinity.Double:
if (t == null) return GetDouble(stmt, index);
return Convert.ChangeType(GetDouble(stmt, index), t, null);
case TypeAffinity.Int64:
if (t == null) return GetInt64(stmt, index);
if (t == typeof(SByte)) return GetSByte(stmt, index);
if (t == typeof(Byte)) return GetByte(stmt, index);
if (t == typeof(Int16)) return GetInt16(stmt, index);
if (t == typeof(UInt16)) return GetUInt16(stmt, index);
if (t == typeof(Int32)) return GetInt32(stmt, index);
if (t == typeof(UInt32)) return GetUInt32(stmt, index);
if (t == typeof(UInt64)) return GetUInt64(stmt, index);
return Convert.ChangeType(GetInt64(stmt, index), t, null);
default:
return GetText(stmt, index);
}
}
/// <summary>
/// Converts a SQLiteType to a .NET Type object
/// </summary>
/// <param name="t">The SQLiteType to convert</param>
/// <returns>Returns a .NET Type object</returns>
internal static Type SQLiteTypeToType(SQLiteType t)
{
if (t.Type != DbType.Object)
return SQLiteConvert.DbTypeToType(t.Type);
return _typeaffinities[(int)t.Affinity];
}
internal abstract object GetValue(SQLiteStatement stmt, int index, SQLiteType typ);
/// <summary>
/// Helper function to retrieve a column of data from an active statement.
/// </summary>
/// <param name="stmt">The statement being step()'d through</param>
/// <param name="index">The column index to retrieve</param>
/// <param name="typ">The type of data contained in the column. If Uninitialized, this function will retrieve the datatype information.</param>
/// <returns>Returns the data in the column</returns>
internal virtual object GetValue(SQLiteStatement stmt, int index, ref SQLiteType typ)
{
if (typ.Affinity == 0) typ = SQLiteConvert.ColumnToType(stmt, index);
if (IsNull(stmt, index)) return DBNull.Value;
Type t = SQLiteConvert.SQLiteTypeToType(typ);
switch (TypeToAffinity(t))
{
case TypeAffinity.Blob:
if (typ.Type == DbType.Guid && typ.Affinity == TypeAffinity.Text)
return new Guid(GetText(stmt, index));
int n = (int)GetBytes(stmt, index, 0, null, 0, 0);
byte[] b = new byte[n];
GetBytes(stmt, index, 0, b, 0, n);
if (typ.Type == DbType.Guid && n == 16)
return new Guid(b);
return b;
case TypeAffinity.DateTime:
return GetDateTime(stmt, index);
case TypeAffinity.Double:
return Convert.ChangeType(GetDouble(stmt, index), t, null);
case TypeAffinity.Int64:
return Convert.ChangeType(GetInt64(stmt, index), t, null);
default:
return GetText(stmt, index);
}
}
internal abstract object GetValue(SQLiteStatement stmt, int index, SQLiteType typ);
internal abstract object GetValue(SQLiteStatement stmt, SQLiteConnectionFlags flags, int index, SQLiteType typ);
/// <summary>
/// Retrieves the SQLiteType for a given column, and caches it to avoid repetetive interop calls.
/// </summary>
/// <param name="i">The index of the column to retrieve</param>
/// <returns>A SQLiteType structure</returns>
private SQLiteType GetSQLiteType(int i)
{
SQLiteType typ;
// Initialize the field types array if not already initialized
if (_fieldTypeArray == null)
_fieldTypeArray = new SQLiteType[VisibleFieldCount];
// Initialize this column's field type instance
if (_fieldTypeArray[i] == null) _fieldTypeArray[i] = new SQLiteType();
typ = _fieldTypeArray[i];
// If not initialized, then fetch the declared column datatype and attempt to convert it
// to a known DbType.
if (typ.Affinity == TypeAffinity.Uninitialized)
typ.Type = SQLiteConvert.TypeNameToDbType(_activeStatement._sql.ColumnType(_activeStatement, i, out typ.Affinity));
else
typ.Affinity = _activeStatement._sql.ColumnAffinity(_activeStatement, i);
return typ;
}
internal abstract object GetValue(SQLiteStatement stmt, SQLiteConnectionFlags flags, int index, SQLiteType typ);
/// <summary>
/// Converts a SQLiteType to a .NET Type object
/// </summary>
/// <param name="t">The SQLiteType to convert</param>
/// <returns>Returns a .NET Type object</returns>
internal static Type SQLiteTypeToType(SQLiteType t)
{
if (t.Type == DbType.Object)
return _affinitytotype[(int)t.Affinity];
else
return SQLiteConvert.DbTypeToType(t.Type);
}
/// <summary>
/// Helper function to retrieve a column of data from an active statement.
/// </summary>
/// <param name="stmt">The statement being step()'d through</param>
/// <param name="index">The column index to retrieve</param>
/// <param name="typ">The type of data contained in the column. If Uninitialized, this function will retrieve the datatype information.</param>
/// <returns>Returns the data in the column</returns>
internal override object GetValue(SQLiteStatement stmt, int index, SQLiteType typ)
{
if (IsNull(stmt, index))
{
return(DBNull.Value);
}
TypeAffinity aff = typ.Affinity;
Type t = null;
if (typ.Type != DbType.Object)
{
t = SQLiteConvert.SQLiteTypeToType(typ);
aff = TypeToAffinity(t);
}
switch (aff)
{
case TypeAffinity.Blob:
if (typ.Type == DbType.Guid && typ.Affinity == TypeAffinity.Text)
{
return(new Guid(GetText(stmt, index)));
}
int n = (int)GetBytes(stmt, index, 0, null, 0, 0);
byte[] b = new byte[n];
GetBytes(stmt, index, 0, b, 0, n);
if (typ.Type == DbType.Guid && n == 16)
{
return(new Guid(b));
}
return(b);
case TypeAffinity.DateTime:
return(GetDateTime(stmt, index));
case TypeAffinity.Double:
if (t == null)
{
return(GetDouble(stmt, index));
}
else
{
return(Convert.ChangeType(GetDouble(stmt, index), t, null));
}
case TypeAffinity.Int64:
if (t == null)
{
return(GetInt64(stmt, index));
}
else
{
return(Convert.ChangeType(GetInt64(stmt, index), t, null));
}
default:
return(GetText(stmt, index));
}
}
internal static void ColumnToType(SQLiteStatement stmt, int i, SQLiteType typ)
{
typ.Type = TypeNameToDbType(stmt._sql.ColumnType(stmt, i, out typ.Affinity));
}
/// <summary>
/// Determines the data type of a column in a statement
/// </summary>
/// <param name="stmt">The statement to retrieve information for</param>
/// <param name="i">The column to retrieve type information on</param>
/// <param name="typ">The SQLiteType to receive the affinity for the given column</param>
internal static void ColumnToType(SQLiteStatement stmt, int i, SQLiteType typ)
{
typ.Type = TypeNameToDbType(stmt._sql.ColumnType(stmt, i, out typ.Affinity));
}
/// <summary>
/// Helper function to retrieve a column of data from an active statement.
/// </summary>
/// <param name="stmt">The statement being step()'d through</param>
/// <param name="index">The column index to retrieve</param>
/// <param name="typ">The type of data contained in the column. If Uninitialized, this function will retrieve the datatype information.</param>
/// <returns>Returns the data in the column</returns>
internal override object GetValue(SQLiteStatement stmt, int index, SQLiteType typ)
{
if (IsNull(stmt, index)) return DBNull.Value;
TypeAffinity aff = typ.Affinity;
Type t = null;
if (typ.Type != DbType.Object)
{
t = SQLiteConvert.SQLiteTypeToType(typ);
aff = TypeToAffinity(t);
}
switch (aff)
{
case TypeAffinity.Blob:
if (typ.Type == DbType.Guid && typ.Affinity == TypeAffinity.Text)
return new Guid(GetText(stmt, index));
int n = (int)GetBytes(stmt, index, 0, null, 0, 0);
byte[] b = new byte[n];
GetBytes(stmt, index, 0, b, 0, n);
if (typ.Type == DbType.Guid && n == 16)
return new Guid(b);
return b;
case TypeAffinity.DateTime:
return GetDateTime(stmt, index);
case TypeAffinity.Double:
if (t == null) return GetDouble(stmt, index);
else
return Convert.ChangeType(GetDouble(stmt, index), t, null);
case TypeAffinity.Int64:
if (t == null) return GetInt64(stmt, index);
else
return Convert.ChangeType(GetInt64(stmt, index), t, null);
default:
return GetText(stmt, index);
}
}
