using Ant.Core; using Ant.DbExpressions; using System; using System.Collections; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Linq; using System.Reflection; using System.Text; namespace Ant.SQLite { partial class SqlGenerator : DbExpressionVisitor { static string GenParameterName(int ordinal) { if (ordinal < CacheParameterNames.Count) { return CacheParameterNames[ordinal]; } return ParameterPrefix + ordinal.ToString(); } static Stack GatherBinaryExpressionOperand(DbBinaryExpression exp) { DbExpressionType nodeType = exp.NodeType; Stack items = new Stack(); items.Push(exp.Right); DbExpression left = exp.Left; while (left.NodeType == nodeType) { exp = (DbBinaryExpression)left; items.Push(exp.Right); left = exp.Left; } items.Push(left); return items; } static void EnsureMethodDeclaringType(DbMethodCallExpression exp, Type ensureType) { if (exp.Method.DeclaringType != ensureType) throw UtilExceptions.NotSupportedMethod(exp.Method); } static void EnsureMethod(DbMethodCallExpression exp, MethodInfo methodInfo) { if (exp.Method != methodInfo) throw UtilExceptions.NotSupportedMethod(exp.Method); } static void EnsureTrimCharArgumentIsSpaces(DbExpression exp) { var m = exp as DbMemberExpression; if (m == null) throw new NotSupportedException(); DbParameterExpression p; if (!DbExpressionExtensions.TryParseToParameterExpression(m, out p)) { throw new NotSupportedException(); } var arg = p.Value; if (arg == null) throw new NotSupportedException(); var chars = arg as char[]; if (chars.Length != 1 || chars[0] != ' ') { throw new NotSupportedException(); } } static bool TryGetCastTargetDbTypeString(Type sourceType, Type targetType, out string dbTypeString, bool throwNotSupportedException = true) { dbTypeString = null; sourceType = Utils.GetUnderlyingType(sourceType); targetType = Utils.GetUnderlyingType(targetType); if (sourceType == targetType) return false; if (CastTypeMap.TryGetValue(targetType, out dbTypeString)) { return true; } if (throwNotSupportedException) throw new NotSupportedException(AppendNotSupportedCastErrorMsg(sourceType, targetType)); else return false; } static string AppendNotSupportedCastErrorMsg(Type sourceType, Type targetType) { return string.Format("Does not support the type '{0}' converted to type '{1}'.", sourceType.FullName, targetType.FullName); } static void DbFunction_DATEADD(SqlGenerator generator, string interval, DbMethodCallExpression exp) { /* DATETIME(@P_0,'+' || 1 || ' years') */ generator._sqlBuilder.Append("DATETIME("); exp.Object.Accept(generator); generator._sqlBuilder.Append(",'+' || "); exp.Arguments[0].Accept(generator); generator._sqlBuilder.Append(" || ' ", interval, "'"); generator._sqlBuilder.Append(")"); } static void DbFunction_DATEPART(SqlGenerator generator, string interval, DbExpression exp) { /* CAST(STRFTIME('%M','2016-08-06 09:01:24') AS INTEGER) */ generator._sqlBuilder.Append("CAST("); generator._sqlBuilder.Append("STRFTIME('%", interval, "',"); exp.Accept(generator); generator._sqlBuilder.Append(")"); generator._sqlBuilder.Append(" AS INTEGER)"); } #region AggregateFunction static void Aggregate_Count(SqlGenerator generator) { generator._sqlBuilder.Append("COUNT(1)"); } static void Aggregate_LongCount(SqlGenerator generator) { generator._sqlBuilder.Append("COUNT(1)"); } static void Aggregate_Max(SqlGenerator generator, DbExpression exp, Type retType) { AppendAggregateFunction(generator, exp, retType, "MAX", false); } static void Aggregate_Min(SqlGenerator generator, DbExpression exp, Type retType) { AppendAggregateFunction(generator, exp, retType, "MIN", false); } static void Aggregate_Sum(SqlGenerator generator, DbExpression exp, Type retType) { AppendAggregateFunction(generator, exp, retType, "SUM", true); } static void Aggregate_Average(SqlGenerator generator, DbExpression exp, Type retType) { AppendAggregateFunction(generator, exp, retType, "AVG", true); } static void AppendAggregateFunction(SqlGenerator generator, DbExpression exp, Type retType, string functionName, bool withCast) { string dbTypeString = null; if (withCast == true) { Type unType = Utils.GetUnderlyingType(retType); if (unType != UtilConstants.TypeOfDecimal/* We don't know the precision and scale,so,we can not cast exp to decimal,otherwise cause problems. */ && CastTypeMap.TryGetValue(unType, out dbTypeString)) { generator._sqlBuilder.Append("CAST("); } } generator._sqlBuilder.Append(functionName, "("); exp.Accept(generator); generator._sqlBuilder.Append(")"); if (dbTypeString != null) { generator._sqlBuilder.Append(" AS ", dbTypeString, ")"); } } #endregion } }