SqlWhereAttribute Class

.NET Standard 2.x

Sets the search condition for the result set when a model class loads the data.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Inheritance Constructor

System.Attribute

Syntax

   [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct)]
   public class SqlWhereAttribute : Attribute

Constructors

Name	Description
SqlWhereAttribute(string rawCondition)	Initializes a new instance of the SqlWhereAttribute class.
SqlWhereAttribute(string left, string right)	Initializes a new instance of the SqlWhereAttribute class.

Properties

Name	Return Type	Description
Left	string	Gets the raw SQL expressions on the left of the operator property.
Operator	SqlBinaryOperator	Gets or sets the operator used in the WHERE clause of the raw SQL.
RawCondition	string	Gets the raw SQL search condition in the WHERE clause without the keyword WHERE.
RawConditionDefined	bool	Gets whether the current instance of the SqlWhere attribute is initialized by a raw SQL search condition.
Right	string	Gets the raw SQL expression on the right of the operator property.

Remarks

The SqlWhere attribute is equivalent to adding a WHERE clause (that defines the search condition for the result set) to the SQL SELECT statement of the model class.

Examples

The following code example demonstrates how to use the SqlWhere attribute. It applies a SqlWhere attribute to the DepartmentSqlWhere class, to add the WHERE clause to the SQL SELECT statement.

Model: DepartmentSqlWhere

using SnapObjects.Data;
using System;
using System.ComponentModel.DataAnnotations;

namespace Appeon.ApiDoc.Models.School
{
    /// <summary>
    /// This model class maps to the dbo.Department table.
    /// </summary>
    [FromTable("Department", Schema = "dbo")]
    [SqlWhere("DepartmentID =1")]
    public class DepartmentSqlWhere
    {
        [Key]
        public int DepartmentID { get; set; }

        public string Name { get; set; }

        public decimal Budget { get; set; }

        public DateTime StartDate { get; set; }

        public int? Administrator { get; set; }

    }
}

Example Method:

using SnapObjects.Data;
using Appeon.ApiDoc.Models.School;
using System;

namespace Appeon.ApiDoc.SqlWhereAttributeExamples
{
    public class SqlWhereAttributeExample
    {
        private SchoolContext _context;

        public SqlWhereAttributeExample(SchoolContext dataContext)
        {
            // Sets the data context.
            _context = dataContext;
        }

        public void Example()
        {
            // Gets the SQL statement. 
            string sql = ModelSqlBuilder.GetBuilder<DepartmentSqlWhere>(_context).QuerySql;

            Console.WriteLine("SQL statement:");
            Console.WriteLine(sql);

            // Executes the SQL statement.
            var departments = _context.SqlExecutor.Select<DepartmentSqlWhere>(sql);

            /* This code example produces the following output:
            
            SQL statement:
            SELECT
             [DepartmentID],
            [Name],
            [Budget],
            [StartDate],
            [Administrator]
            FROM [dbo].[Department]
            WHERE ([DepartmentID] =1)
            */
        }
    }
}

Applies to

.NET Standard

2.x