// Delete methods
public async Task <int> DeleteAsync(string deleteStatement, dynamic vars)
{
DeleteStatement statement = new DeleteStatement(this.database, deleteStatement);
return(await this.DeleteAsync(statement, vars));
}
public async Task <int> DeleteAsync(DeleteStatement deleteStatement, dynamic vars)
{
Dict varsDict = deleteStatement.ConvertParamsToDict(vars);
(var whereIndex, var whereRefs) = deleteStatement.GetWhereIndexAndWhereRefs(this.database, varsDict);
(string executableSql, Dict executableParams) = deleteStatement.GetExecutableSqlAndParams(varsDict, whereRefs);
var tableName = deleteStatement.StatementFromRefs[0].table.Name;
var primaryIndex = deleteStatement.StatementFromRefs[0].table.Indexes[0];
object keyValue = await this.GetKeyValue(whereIndex, varsDict, executableParams, whereRefs, primaryIndex, tableName);
Dict record = null;
var deleteForeignKeys = this.database.GetForeignKeys(tableName, ForeignKeyRule.DeleteChildOnParentDelete, ForeignKeyRule.NullChildOnParentDelete);
if (deleteForeignKeys.Length > 0)
{
record = await this.database.SelectRowAsync(tableName, keyValue);
}
int count;
if (keyValue == null)
{
count = 0;
}
else
{
count = await this.DoDeleteAsync(executableSql, executableParams);
if (count > 0)
{
this.dataEvents.Add(new KeyValueDataEvent(DataEventType.Delete, tableName, keyValue));
foreach (var foreignKey in deleteForeignKeys)
{
var childSelectValues = new Dict();
for (int i = 0; i < foreignKey.parentFieldNames.Length; i++)
{
childSelectValues[foreignKey.childFieldNames[i]] = record[foreignKey.parentFieldNames[i]];
}
var childRecords = await this.database.SelectRowsAsync(foreignKey.childTable.Name, childSelectValues);
foreach (var childRecord in childRecords)
{
Dict modifyValues = new Dict();
foreach (var childPrimaryKeyFieldName in foreignKey.childTable.Indexes[0].FieldNames)
{
modifyValues[childPrimaryKeyFieldName] = childRecord[childPrimaryKeyFieldName];
}
switch (foreignKey.foreignKeyRule)
{
case ForeignKeyRule.DeleteChildOnParentDelete:
await this.DeleteAsync(foreignKey.childTable.Name, modifyValues);
break;
case ForeignKeyRule.NullChildOnParentDelete:
for (int i = 0; i < foreignKey.parentFieldNames.Length; i++)
{
modifyValues[foreignKey.childFieldNames[i]] = null;
}
await this.UpdateAsync(foreignKey.childTable.Name, modifyValues);
break;
}
}
}
}
this.database.DeleteCount++;
}
return(count);
}
