SqlTriggerAttribute.cs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See License.txt in the project root for license information.

using System;
using Microsoft.Azure.WebJobs.Description;

namespace Microsoft.Azure.WebJobs
{
    /// <summary>
    /// Attribute used to bind a parameter to SQL trigger message.
    /// </summary>
    [Binding]
    [AttributeUsage(AttributeTargets.Parameter)]
    public sealed class SqlTriggerAttribute : Attribute
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="SqlTriggerAttribute"/> class, which triggers the function when any changes on the specified table are detected.
        /// </summary>
        /// <param name="tableName">Name of the table to watch for changes.</param>
        /// <param name="connectionStringSetting">The name of the app setting where the SQL connection string is stored</param>
        /// <param name="leasesTableName">Optional - The name of the table used to store leases. If not specified, the leases table name will be Leases_{FunctionId}_{TableId}</param>
        public SqlTriggerAttribute(string tableName, string connectionStringSetting, string leasesTableName = null)
        {
            this.TableName = tableName ?? throw new ArgumentNullException(nameof(tableName));
            this.ConnectionStringSetting = connectionStringSetting ?? throw new ArgumentNullException(nameof(connectionStringSetting));
            this.LeasesTableName = leasesTableName;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="SqlTriggerAttribute"/> class with null value for LeasesTableName.
        /// </summary>
        /// <param name="tableName">Name of the table to watch for changes.</param>
        /// <param name="connectionStringSetting">The name of the app setting where the SQL connection string is stored</param>
        public SqlTriggerAttribute(string tableName, string connectionStringSetting) : this(tableName, connectionStringSetting, null) { }

        /// <summary>
        /// Name of the app setting containing the SQL connection string.
        /// </summary>
        [ConnectionString]
        public string ConnectionStringSetting { get; }

        /// <summary>
        /// Name of the table to watch for changes.
        /// </summary>
        public string TableName { get; }

        /// <summary>
        /// Name of the table used to store leases.
        /// If not specified, the leases table name will be Leases_{FunctionId}_{TableId}
        /// More information on how this is generated can be found here
        /// https://github.com/Azure/azure-functions-sql-extension/blob/main/docs/TriggerBinding.md#az_funcleasestablename
        /// </summary>
        public string LeasesTableName { get; }
    }
}