给 EF Core 查询增加 With NoLock

有点小问题，正则表达式不支持子查询；

略作修改。

using Microsoft.EntityFrameworkCore.Diagnostics;
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;



public class QueryWithNoLockDbCommandInterceptor : DbCommandInterceptor
    {
        private static readonly Regex TableAliasRegex =
            new Regex(@"(?<tableAlias>(FROM|JOIN) \[[a-zA-Z]\w*\] AS \[[a-zA-Z]\w*\](?! WITH \(NOLOCK\)))",
                RegexOptions.Multiline | RegexOptions.Compiled | RegexOptions.IgnoreCase);

        public override InterceptionResult<object> ScalarExecuting(DbCommand command, CommandEventData eventData, InterceptionResult<object> result)
        {
            command.CommandText = TableAliasRegex.Replace(
                command.CommandText,
                "${tableAlias} WITH (NOLOCK)"
                );
            return base.ScalarExecuting(command, eventData, result);
        }

        public override ValueTask<InterceptionResult<object>> ScalarExecutingAsync(DbCommand command, CommandEventData eventData, InterceptionResult<object> result,
            CancellationToken cancellationToken = new CancellationToken())
        {
            command.CommandText = TableAliasRegex.Replace(
                command.CommandText,
                "${tableAlias} WITH (NOLOCK)"
                );
            return base.ScalarExecutingAsync(command, eventData, result, cancellationToken);
        }

        public override InterceptionResult<DbDataReader> ReaderExecuting(DbCommand command, CommandEventData eventData, InterceptionResult<DbDataReader> result)
        {
            command.CommandText = TableAliasRegex.Replace(
                command.CommandText,
                "${tableAlias} WITH (NOLOCK)"
                );
            return result;
        }

        public override ValueTask<InterceptionResult<DbDataReader>> ReaderExecutingAsync(DbCommand command, CommandEventData eventData, InterceptionResult<DbDataReader> result,
            CancellationToken cancellationToken = new CancellationToken())
        {
            command.CommandText = TableAliasRegex.Replace(
                command.CommandText,
                "${tableAlias} WITH (NOLOCK)"
                );
            return base.ReaderExecutingAsync(command, eventData, result, cancellationToken);
        }
    }

dbcontext上加上这个拦截器

var services = new ServiceCollection();
services.AddDbContext<TestDbContext>(options =>
{
    options
        .UseLoggerFactory(loggerFactory)
        .UseSqlServer(DbConnectionString)
        .AddInterceptors(new QueryWithNoLockDbCommandInterceptor())
        ;
});

作者：沐雪
文章均系作者原创或翻译，如有错误不妥之处，欢迎各位批评指正。本文版权归作者所有，如需转载恳请注明。 如果您觉得阅读这篇博客让你有所收获
​​​ 为之网-热爱软件编程 http://www.weizhi.cc/​​