public static SqlTableDefinition GetTableDefinition(this Sqlite3SchemaRow schema)
{
Dictionary <Sqlite3SchemaRow, SqlTableDefinition> definitionCache = schema.Database.GetProperty(SqlCacheKey, () => new Dictionary <Sqlite3SchemaRow, SqlTableDefinition>());
if (!definitionCache.TryGetValue(schema, out SqlTableDefinition definition))
{
if (!SqlParser.TryParse(schema.Sql, out definition))
{
definitionCache[schema] = null;
}
else
{
definitionCache[schema] = definition;
}
}
if (definition == null)
{
throw new Exception();
}
SqlTableDefinition def = definition;
return(def);
}
public static bool TryGetValueByName(this Sqlite3Row row, string columnName, out object value)
{
value = null;
SqlTableDefinition tableDefinition = row.Table.GetTableDefinition();
if (!tableDefinition.TryGetColumn(columnName, out SqlTableColumn column))
{
return(false);
}
if (row.ColumnData.Length <= column.Ordinal)
{
return(false);
}
// Special case for row-id
if (tableDefinition.RowIdColumn != null && columnName.Equals(tableDefinition.RowIdColumn.Name, StringComparison.OrdinalIgnoreCase))
{
// Return the row-id
value = row.RowId;
return(true);
}
value = row.ColumnData[column.Ordinal];
return(true);
}
public static bool TryParse(string sql, out SqlTableDefinition tableDefinition)
{
tableDefinition = null;
// Parse out the SQL into series of column creation statements
Result <TokenList <SqlToken> > tokens = SqlTokenizer.Tokenizer.TryTokenize(sql);
if (!tokens.HasValue)
{
return(false);
}
if (!TryParseTokenList(tokens.Value, out SqlNode node))
{
return(false);
}
// Check if this is a create table
if (!node.Is(0, "CREATE") || !node.Is(1, "TABLE") || !node.Is(2, SqlToken.String) || !node.IsGroup(3))
{
return(false);
}
SqlTableDefinition def = new SqlTableDefinition(node.GetString(2));
SqlNode columns = node.GetGroup(3);
int primaryKeyComponents = 0;
SqlTableColumn primaryKeyColumn = null;
for (int columnIndex = 0; columnIndex < columns.Children.Count; columnIndex++)
{
SqlNode columnSet = columns.Children[columnIndex];
if (!columnSet.Children.Any() || !columnSet.Children.First().Is(SqlToken.String))
{
continue;
}
string firstToken = columnSet.Children.First().GetString();
bool isConstraint = SqlKeywords.NonColumnKeywords.Contains(firstToken);
string name;
if (isConstraint)
{
if (columnSet.Is(0, "PRIMARY") && columnSet.Is(1, "KEY") && columnSet.IsGroup(2))
{
SqlNode pkColumns = columnSet.GetGroup(2);
foreach (SqlNode pkColumn in pkColumns.Children)
{
if (pkColumn.Is(SqlToken.String))
{
name = pkColumn.GetString();
}
else if (pkColumn.Is(0, SqlToken.String))
{
name = pkColumn.GetString(0);
}
else
{
return(false);
}
if (!def.TryGetColumn(name, out SqlTableColumn columnObject))
{
continue;
}
columnObject.IsPartOfPrimaryKey = true;
primaryKeyComponents++;
primaryKeyColumn = columnObject;
}
}
continue;
}
name = columnSet.GetString(0);
string[] typeStrings = columnSet.Children.Skip(1).Where(s => s.Is(SqlToken.String))
.Select(s => s.GetString()).ToArray();
// Defaults
Type identifiedType = typeof(byte[]);
string[] identifiedTypeStrings = typeStrings;
foreach ((string[] words, Type type)candidate in SqlKeywords.TypeKeywords)
{
if (!typeStrings.Take(candidate.words.Length).SequenceEqual(candidate.words))
{
continue;
}
identifiedType = candidate.type;
identifiedTypeStrings = candidate.words;
break;
}
SqlTableColumn sqlTableColumn = new SqlTableColumn(columnIndex, name, string.Join(" ", identifiedTypeStrings), identifiedType);
def.AddColumn(sqlTableColumn);
// Is this a primary key?
if (typeStrings.Contains("PRIMARY", StringComparer.OrdinalIgnoreCase) &&
typeStrings.Contains("KEY", StringComparer.OrdinalIgnoreCase))
{
sqlTableColumn.IsPartOfPrimaryKey = true;
primaryKeyComponents++;
primaryKeyColumn = sqlTableColumn;
}
}
// Identify row-id substitutes
if (primaryKeyComponents == 1 && primaryKeyColumn.DetectedType == typeof(long))
{
def.ConfigureRowIdColumn(primaryKeyColumn);
}
tableDefinition = def;
return(true);
}