DataView的RowFilter用法
DataView RowFilter Syntax [C#]
This example describes syntax of DataView.RowFilter expression. It shows how to correctly build expression string (without „SQL injection“) using methods to escape values.
Column names
If a column name contains any of these special characters ~ ( ) # / / = > < + - * % & | ^ ' " [ ], you must enclose the column name within square brackets [ ]. If a column name contains right bracket ] or backslash /, escape it with backslash (/] or //).
[C#]
dataView.RowFilter = "id = 10"; // no special character in column name "id" dataView.RowFilter = "$id = 10"; // no special character in column name "$id" dataView.RowFilter = "[#id] = 10"; // special character "#" in column name "#id" dataView.RowFilter = "[[id/]] = 10"; // special characters in column name "[id]"
Literals
String values are enclosed within single quotes ' '. If the string contains single quote ', the quote must be doubled.
[C#]
dataView.RowFilter = "Name = 'John'" // string value dataView.RowFilter = "Name = 'John ''A'''" // string with single quotes "John 'A'" dataView.RowFilter = String.Format("Name = '{0}'", "John 'A'".Replace("'", "''"));
Number values are not enclosed within any characters. The values should be the same as is the result of int.ToString() or float.ToString() method for invariant or English culture.
[C#]
dataView.RowFilter = "Year = 2008" // integer value dataView.RowFilter = "Price = 1199.9" // float value dataView.RowFilter = String.Format(CultureInfo.InvariantCulture.NumberFormat, "Price = {0}", 1199.9f);
Date values are enclosed within sharp characters # #. The date format is the same as is the result of DateTime.ToString() method for invariant or English culture.
[C#]
dataView.RowFilter = "Date = #12/31/2008#" // date value (time is 00:00:00) dataView.RowFilter = "Date = #2008-12-31#" // also this format is supported dataView.RowFilter = "Date = #12/31/2008 16:44:58#" // date and time value dataView.RowFilter = String.Format(CultureInfo.InvariantCulture.DateTimeFormat, "Date = #{0}#", new DateTime(2008, 12, 31, 16, 44, 58));
Alternatively you can enclose all values within single quotes ' '. It means you can use string values for numbers or date time values. In this case the current culture is used to convert the string to the specific value.
[C#]
dataView.RowFilter = "Date = '12/31/2008 16:44:58'" // if current culture is English dataView.RowFilter = "Date = '31.12.2008 16:44:58'" // if current culture is German dataView.RowFilter = "Price = '1199.90'" // if current culture is English dataView.RowFilter = "Price = '1199,90'" // if current culture is German
Comparison operators
Equal, not equal, less, greater operators are used to include only values that suit to a comparison expression. You can use these operators = <> < <= > >=.
Note: String comparison is culture-sensitive, it uses CultureInfo from DataTable.Locale property of related table (dataView.Table.Locale). If the property is not explicitly set, its default value is DataSet.Locale (and its default value is current system culture Thread.CurrentThread.CurrentCulture).
[C#]
dataView.RowFilter = "Num = 10" // number is equal to 10 dataView.RowFilter = "Date < #1/1/2008#" // date is less than 1/1/2008 dataView.RowFilter = "Name <> 'John'" // string is not equal to 'John' dataView.RowFilter = "Name >= 'Jo'" // string comparison
Operator IN is used to include only values from the list. You can use the operator for all data types, such as numbers or strings.
[C#]
dataView.RowFilter = "Id IN (1, 2, 3)" // integer values dataView.RowFilter = "Price IN (1.0, 9.9, 11.5)" // float values dataView.RowFilter = "Name IN ('John', 'Jim', 'Tom')" // string values dataView.RowFilter = "Date IN (#12/31/2008#, #1/1/2009#)" // date time values dataView.RowFilter = "Id NOT IN (1, 2, 3)" // values not from the list
Operator LIKE is used to include only values that match a pattern with wildcards. Wildcard character is * or %, it can be at the beginning of a pattern '*value', at the end 'value*', or at both '*value*'. Wildcard in the middle of a patern 'va*lue' is not allowed.
[C#]
dataView.RowFilter = "Name LIKE 'j*'" // values that start with 'j' dataView.RowFilter = "Name LIKE '%jo%'" // values that contain 'jo' dataView.RowFilter = "Name NOT LIKE 'j*'" // values that don't start with 'j'
If a pattern in a LIKE clause contains any of these special characters * %