protected override IEnumerable <Column> GetColumns(IDatabase database, RestrictionDictionary restrictionValues)
{
var parameters = new ParameterCollection();
var columns = new List <Column>();
//如果指定使用表名查询
if (restrictionValues.TryGetValue(nameof(Column.TableName), out string tableName))
{
SqlCommand sql = $@"
PRAGMA main.TABLE_INFO('{tableName}')";
columns.AddRange(GetColumns(database, tableName));
}
else
{
//循环所有表，对每个表进行查询
foreach (var tb in GetTables(database, RestrictionDictionary.Empty))
{
SqlCommand sql = $@"
PRAGMA main.TABLE_INFO('{tb.Name}')";
columns.AddRange(GetColumns(database, tb.Name));
}
}
//如果使用列名进行查询
if (restrictionValues.TryGetValue(nameof(Column.Name), out string columnName))
{
columns = columns.Where(s => s.Name == columnName).ToList();
}
return(columns);
}
protected override IEnumerable <Database> GetDatabases(IDatabase database, RestrictionDictionary restrictionValues)
{
var sql = "SHOW DATABASES";
if (restrictionValues.TryGetValue(nameof(Database.Name), out string dbName))
{
sql += $" LIKE '{dbName}'";
}
return(ExecuteAndParseMetadata(database, sql, null, (wrapper, reader) => new Database
{
Name = wrapper.GetString(reader, 0)
}));
}
protected override IEnumerable <ForeignKey> GetForeignKeys(IDatabase database, RestrictionDictionary restrictionValues)
{
var parameters = new ParameterCollection();
//如果指定使用表名查询
if (restrictionValues.TryGetValue(nameof(ForeignKey.TableName), out string tbName))
{
SqlCommand sql = $@"
PRAGMA main.FOREIGN_KEY_LIST('{tbName}')";
return(ExecuteAndParseMetadata(database, sql, parameters, (wrapper, reader) => new ForeignKey
{
TableName = tbName,
ColumnName = wrapper.GetString(reader, 4),
PKTable = wrapper.GetString(reader, 2),
PKColumn = wrapper.GetString(reader, 3)
}));
}
else
{
var columns = new List <ForeignKey>();
//循环所有表，对每个表进行查询
foreach (var tb in GetTables(database, RestrictionDictionary.Empty))
{
SqlCommand sql = $@"
PRAGMA main.FOREIGN_KEY_LIST('{tb.Name}')";
columns.AddRange(ExecuteAndParseMetadata(database, sql, parameters, (wrapper, reader) => new ForeignKey
{
TableName = tb.Name,
ColumnName = wrapper.GetString(reader, 4),
PKTable = wrapper.GetString(reader, 2),
PKColumn = wrapper.GetString(reader, 3)
}));
}
return(columns);
}
}
