-2146232060 dotnet data_error ai_generated true

Microsoft.Data.SqlClient.SqlException (0x80131904): Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

ID: dotnet/ef-core-sql-timeout

Also available as: JSON · Markdown · 中文

85%Fix Rate

88%Confidence

1Evidence

2023-06-01First Seen

Version Compatibility

Version	Status	Introduced	Deprecated	Notes
.NET 6.0	active	—	—	—
.NET 7.0	active	—	—	—
.NET 8.0	active	—	—	—
EF Core 6.0	active	—	—	—
EF Core 7.0	active	—	—	—
EF Core 8.0	active	—	—	—

Root Cause

Entity Framework Core query or command exceeds the default 30-second command timeout due to complex joins, unindexed queries, or large result sets in SQL Server.

generic

中文

Entity Framework Core 查询或命令因复杂联接、未索引查询或结果集过大而超过默认的 30 秒命令超时。

Official Documentation

https://learn.microsoft.com/en-us/dotnet/api/system.data.sqlclient.sqlexception

Workarounds

90% success Add database indexes on columns used in WHERE and JOIN clauses. Example: CREATE INDEX IX_Orders_CustomerId ON Orders (CustomerId);
```
Add database indexes on columns used in WHERE and JOIN clauses. Example: CREATE INDEX IX_Orders_CustomerId ON Orders (CustomerId);
```
75% success Set CommandTimeout to a higher value (e.g., 120 seconds) in OnConfiguring: optionsBuilder.UseSqlServer(connectionString, opts => opts.CommandTimeout(120));
```
Set CommandTimeout to a higher value (e.g., 120 seconds) in OnConfiguring: optionsBuilder.UseSqlServer(connectionString, opts => opts.CommandTimeout(120));
```
85% success Optimize LINQ query by using .AsSplitQuery() to avoid Cartesian explosion: context.Orders.Include(o => o.Details).AsSplitQuery().ToList();
```
Optimize LINQ query by using .AsSplitQuery() to avoid Cartesian explosion: context.Orders.Include(o => o.Details).AsSplitQuery().ToList();
```

中文步骤

在 WHERE 和 JOIN 子句使用的列上添加数据库索引。示例：CREATE INDEX IX_Orders_CustomerId ON Orders (CustomerId);

在 OnConfiguring 中将 CommandTimeout 设置为更高值（如 120 秒）：optionsBuilder.UseSqlServer(connectionString, opts => opts.CommandTimeout(120));

使用 .AsSplitQuery() 优化 LINQ 查询以避免笛卡尔爆炸：context.Orders.Include(o => o.Details).AsSplitQuery().ToList();

Dead Ends

Common approaches that don't work:

Set CommandTimeout to 0 (infinite) in DbContext options 70% fail
Infinite timeout can cause indefinite hangs and resource exhaustion; it masks the underlying query performance issue.
Add .AsNoTracking() to all queries 85% fail
AsNoTracking reduces overhead but does not fix slow queries; timeout still occurs if the query is slow due to missing indexes.
Increase SqlCommand timeout in appsettings 60% fail
Increasing timeout without optimizing the query or adding indexes only delays the failure; the query may still fail under load.