查看EF CORE 3.1/3.0/2.1.2生成的SQL语句

转载自https://www.cnblogs.com/gskstudy/p/13306399.html

对于EFCore 3.1

using System.Linq;
using System.Reflection;
using System.Collections.Generic;
using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
using Microsoft.EntityFrameworkCore.Query;

public static string ToSql(this IQueryable query) where TEntity : class
{
var enumerator = query.Provider.Execute<IEnumerable>(query.Expression).GetEnumerator();
var relationalCommandCache = enumerator.Private("_relationalCommandCache");
var selectExpression = relationalCommandCache.Private("_selectExpression");
var factory = relationalCommandCache.Private("_querySqlGeneratorFactory");

var sqlGenerator = factory.Create();
var command = sqlGenerator.GetCommand(selectExpression);

string sql = command.CommandText;
return sql;

}

private static object Private(this object obj, string privateField) => obj?.GetType().GetField(privateField, BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(obj);
private static T Private(this object obj, string privateField) => (T)obj?.GetType().GetField(privateField, BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(obj);
　　

对于EFCore 3.0

public static string ToSql(this IQueryable query)
{
var enumerator = query.Provider.Execute<IEnumerable>(query.Expression).GetEnumerator();
var enumeratorType = enumerator.GetType();
var selectFieldInfo = enumeratorType.GetField("_selectExpression", BindingFlags.NonPublic | BindingFlags.Instance) ?? throw new InvalidOperationException($"cannot find field _selectExpression on type {enumeratorType.Name}");
var sqlGeneratorFieldInfo = enumeratorType.GetField("_querySqlGeneratorFactory", BindingFlags.NonPublic | BindingFlags.Instance) ?? throw new InvalidOperationException($"cannot find field _querySqlGeneratorFactory on type {enumeratorType.Name}");
var selectExpression = selectFieldInfo.GetValue(enumerator) as SelectExpression ?? throw new InvalidOperationException($"could not get SelectExpression");
var factory = sqlGeneratorFieldInfo.GetValue(enumerator) as IQuerySqlGeneratorFactory ?? throw new InvalidOperationException($"could not get IQuerySqlGeneratorFactory");
var sqlGenerator = factory.Create();
var command = sqlGenerator.GetCommand(selectExpression);
var sql = command.CommandText;
return sql;
}
　　

对于EFCore 2.1.2

static class IQueryableToSql
{
private static readonly TypeInfo QueryCompilerTypeInfo = typeof(QueryCompiler).GetTypeInfo();
private static readonly FieldInfo QueryCompilerField = typeof(EntityQueryProvider).GetTypeInfo().DeclaredFields.First(x => x.Name == "_queryCompiler");
private static readonly FieldInfo QueryModelGeneratorField = QueryCompilerTypeInfo.DeclaredFields.First(x => x.Name == "_queryModelGenerator");
private static readonly FieldInfo queryContextFactoryField = QueryCompilerTypeInfo.DeclaredFields.First(x => x.Name == "_queryContextFactory");
private static readonly FieldInfo loggerField = QueryCompilerTypeInfo.DeclaredFields.First(x => x.Name == "_logger");
private static readonly FieldInfo DataBaseField = QueryCompilerTypeInfo.DeclaredFields.Single(x => x.Name == "_database");
private static readonly PropertyInfo DatabaseDependenciesField = typeof(Database).GetTypeInfo().DeclaredProperties.Single(x => x.Name == "Dependencies");

        public static (string sql, IReadOnlyDictionary<string, object> parameters) ToSql<TEntity>(IQueryable<TEntity> query) where TEntity : class
        {
            var queryCompiler = (QueryCompiler)QueryCompilerField.GetValue(query.Provider);
            var queryContextFactory = (IQueryContextFactory)queryContextFactoryField.GetValue(queryCompiler);
            var logger = (Microsoft.EntityFrameworkCore.Diagnostics.IDiagnosticsLogger<DbLoggerCategory.Query>)loggerField.GetValue(queryCompiler);
            var queryContext = queryContextFactory.Create();
            var modelGenerator = (QueryModelGenerator)QueryModelGeneratorField.GetValue(queryCompiler);
            var newQueryExpression = modelGenerator.ExtractParameters(logger, query.Expression, queryContext);
            var queryModel = modelGenerator.ParseQuery(newQueryExpression);
            var database = (IDatabase)DataBaseField.GetValue(queryCompiler);
            var databaseDependencies = (DatabaseDependencies)DatabaseDependenciesField.GetValue(database);
            var queryCompilationContext = databaseDependencies.QueryCompilationContextFactory.Create(false);
            var modelVisitor = (RelationalQueryModelVisitor)queryCompilationContext.CreateQueryModelVisitor();

            modelVisitor.CreateQueryExecutor<TEntity>(queryModel);
            var command = modelVisitor.Queries.First().CreateDefaultQuerySqlGenerator()
                .GenerateSql(queryContext.ParameterValues);

            return (command.CommandText, queryContext.ParameterValues);
        }
    }