C# IQueryContext.AddConstraint方法代码示例

//.........这里部分代码省略.........
                        foreach (var unique in uniques) {
                            CheckColumnConstraint(columnName, unique.ColumnNames, TableName, unique.ConstraintName);
                        }

                        markDropped = true;
                        tableAltered = true;
                    }

                    var newColumn = new ColumnInfo(columnName, columnType);
                    if (defaultExpression != null)
                        newColumn.DefaultExpression = defaultExpression;

                    newColumn.IndexType = column.IndexType;
                    newColumn.IsNotNull = column.IsNotNull;

                    // If not dropped then add to the new table definition.
                    if (!markDropped) {
                        newTableInfo.AddColumn(newColumn);
                    }
                }

                if (Action.ActionType == AlterTableActionType.AddColumn) {
                    var col = ((AddColumnAction)Action).Column;

                    checker.CheckExpression(col.DefaultExpression);
                    var columnName = col.ColumnName;
                    var columnType = col.ColumnType;

                    // If column name starts with [table_name]. then strip it off
                    columnName = checker.StripTableName(TableName.Name, columnName);
                    if (tableInfo.IndexOfColumn(col.ColumnName) != -1)
                        throw new InvalidOperationException("The column '" + col.ColumnName + "' is already in the table '" + tableInfo.TableName + "'.");

                    var newColumn = new ColumnInfo(columnName, columnType) {
                        IsNotNull = col.IsNotNull,
                        DefaultExpression = col.DefaultExpression
                    };

                    newTableInfo.AddColumn(newColumn);
                    tableAltered = true;
                }

                if (Action.ActionType == AlterTableActionType.DropConstraint) {
                    string constraintName = ((DropConstraintAction)Action).ConstraintName;
                    int dropCount = context.DropConstraint(TableName, constraintName);
                    if (dropCount == 0)
                        throw new InvalidOperationException("Named constraint to drop on table " + TableName + " was not found: " + constraintName);
                } else if (Action.ActionType == AlterTableActionType.DropPrimaryKey) {
                    if (!context.DropPrimaryKey(TableName))
                        throw new InvalidOperationException("No primary key to delete on table " + TableName);
                }

                if (Action.ActionType == AlterTableActionType.AddConstraint) {
                    var constraint = ((AddConstraintAction)Action).Constraint;
                    bool foreignConstraint = (constraint.ConstraintType == ConstraintType.ForeignKey);

                    ObjectName refTname = null;
                    if (foreignConstraint) {
                        refTname = context.ResolveTableName(constraint.ForeignTable);
                    }

                    var columnNames = checker.StripColumnList(TableName.FullName, constraint.ColumnNames);
                    columnNames = checker.StripColumnList(constraint.ForeignTable.FullName, columnNames);
                    var expression = checker.CheckExpression(constraint.CheckExpression);
                    columnNames = checker.CheckColumns(columnNames);

                    IEnumerable<string> refCols = null;
                    if (foreignConstraint && constraint.ForeignColumnNames != null) {
                        var referencedChecker = ColumnChecker.Default(context, refTname);
                        refCols = referencedChecker.CheckColumns(constraint.ForeignColumnNames);
                    }

                    var newConstraint = new ConstraintInfo(constraint.ConstraintType, constraint.TableName, columnNames.ToArray());
                    if (foreignConstraint) {
                        newConstraint.ForeignTable = refTname;
                        newConstraint.ForeignColumnNames = refCols.ToArray();
                    }

                    if (constraint.ConstraintType == ConstraintType.Check)
                        newConstraint.CheckExpression = expression;

                    context.AddConstraint(TableName, newConstraint);
                }

                // Alter the existing table to the new format...
                if (tableAltered) {
                    if (newTableInfo.ColumnCount == 0)
                        throw new InvalidOperationException("Can not ALTER table to have 0 columns.");

                    context.AlterTable(newTableInfo);
                } else {
                    // If the table wasn't physically altered, check the constraints.
                    // Calling this method will also make the transaction check all
                    // deferred constraints during the next commit.
                    context.CheckConstraints(TableName);
                }

                // Return '0' if everything successful.
                return FunctionTable.ResultTable(context, 0);
            }