Sqlglot expression

Sqlglot expression. Table ) ] Saved searches Use saved searches to filter your results more quickly Dec 6, 2023 · SQLGlot supports annotations in the sql expression. Dot'> and also this error: sqlglot. SQLGlot is a powerful tool for analyzing and transforming SQL, but the learning curve can be intimidating. 439dialect: the SQL dialect that will be used to parse `schema_type`, if needed. sql 'SELECT x FROM z' Parsed expressions can also be transformed recursively by applying a mapping function to each node in the tree: from sqlglot import exp, parse_one expression_tree = parse_one ("SELECT a FROM x") def transformer (node): if isinstance (node, exp. Apr 13, 2023 · where they both dont take into account several measures or definitions. simplify import simplify 5 6 7 def pushdown_predicates (expression, dialect = None): 8 """ 9 Rewrite sqlglot AST to pushdown predicates in FROMS and JOINS 10 11 Example: 12 Parts of SQLGlot's toolkit are being used today by the following: Ibis: A Python library that provides a lightweight, universal interface for data wrangling. end: The ending index of the token. dialect import (5 approx_count_distinct_sql, 6 arrow_json_extract_sql, 7 build_timestamp_trunc, 8 rename_func, 9 unit_to_str, 10) 11 from sqlglot. L_BRACKET: 'L_BRACKET'>, ']': <TokenType. optimizer. Table ) print (. _parse Sep 3, 2021 · SQLGlot is a no dependency Python SQL parser and transpiler. scope import Scope, traverse_scope 10 from sqlglot. parse_one ( "SELECT a FROM db. diff import Insert, Remove import sqlglot. Parser = dia. self. The tree. sql() 'SELECT a FROM (SELECT x. R_BRACKET: 'R SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. start: The start index of the token. 548defsimplify_literals(expression,root Feb 22, 2022 · 1. normalize import normalized 3 from sqlglot. R_PAREN: 'R_PAREN'>, '[': <TokenType. a AND TRUE JOIN y ON y Oct 25, 2021 · 2. 11911192Args:1193raw_tokens: The list of tokens. If you’re using a different database system for which we don’t support column-level lineage out Arguments: token_type: The TokenType Enum. line: The line that the token ends on. It's possible to make this a no-op by adding a special comment next to theidentifier of interest: SELECT a /* sqlglot. x FROM tbl PIVOT (SUM(a) FOR b IN ('x')) piv") 71 >>> print(_unalias DataType:434"""435Convert a type represented as a string to the corresponding `sqlglot. dialects. You can find a complete source code in the diff. It is currently the fastest pure-Python SQL parser. parse(query)[0]. Before you file an Aug 24, 2023 · Him can easily customize the parser, analyze queries, traverse expression trees, and programmatically building SQL. Parses the given SQL string in accordance with the source dialect and returns a list of SQL strings transformed. If you’re already a user of DataHub 0. helper import ensure_list The implementation discussed in this post is now a part of the SQLGlot library. dialect import DialectType 8 from sqlglot. 1 from __future__ import annotations 2 3 from sqlglot import exp 4 from sqlglot. 91 92 This is used as an estimate of the cost of the conversion which is exponential in complexity. Possibility for improvement: Use typeof function to get the type of the column and check if it matches the type of the value provided. dialect import merge_without_target_sql, trim_sql 5 from sqlglot. Fwiw the second example does work as expected: >>> import sqlglot >>> sqlglot. This post is intended to familiarize newbies with SQLGlot's abstract syntax trees, how to traverse them, and how to mutate them. It aims to read a wide variety of SQL inputs and output syntactically correct SQL in the targeted dialects. alias for i in sqlglot. mysql import MySQL 12 from sqlglot. a FROM x) CROSS JOIN y' Use the subtraction and addition properties of equality to simplify expressions: x + 1 = 3 becomes x = 2. def find_selected_columns(query) -> list[str]: tokens = sqlparse. optimizer 1 from sqlglot import exp 2 from sqlglot. In code, that reads like. spark2 import Spark2, temporary_storage_provider, _build_as_cast 9 from sqlglot. ate or replace view my_view ( "USER_ID", "GUEST_IND", "FIRST_ORDER_DATE_TIME_UTC" ) copy grants AS ( SELECT USER_ID, GUEST_IND, FIRST_ORDER_DATE_TIME_UTC FROM (select * fro ``` If I remove `copy grants` from the query it works. parse_one(s). mysql View Source. Nov 9, 2023 · Required keyword: 'this' missing for <class 'sqlglot. 443"""444ifschema_typenotinself. identify: Determines when an identifier should be quoted. If not then make it null. This flag will cause the CTE alias columns to override any projection aliases in the subquery. CommentColumnConstraint'> with Snowflake #2539 Closed braunreyes opened this issue Nov 9, 2023 · 2 comments · Fixed by #2542 SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. 1 from __future__ import annotations 2 3 import typing as t 4 5 from sqlglot import exp, generator, parser, tokens, transforms 6 from sqlglot. MATCH_RECOGNIZE): return None. Expression: 64 """ 65 Spark doesn't allow PIVOT aliases, so we need to remove them and possibly wrap a 66 pivoted source in a subquery with the same alias to preserve the query's semantics. annotators: Maps expression type to corresponding annotation function. The difficulty stems from the fact that when you pivot a table, you have some columns that are produced as a function of the value list (i. coerces_to: Maps expression type to set of types that it can be coerced into. SINGLE_TOKENS = {'(': <TokenType. from_ ("z"). 2. DELETE parsing is only partially supported as of v1. Fully reproducible code snippet sql = '''WITH test AS (SELECT 'abc' AS values) SELECT STRUCT(values AS v) FROM test''' sqlglot . parse ( sql , read = 'bigquery' ) Hi Toby, Thanks for your work on this. def update_query(ast, find_tbl, replace_tbl): if isinstance(ast, (sqlglot. 67 68 Example: 69 >>> from sqlglot import parse_one 70 >>> expr = parse_one("SELECT piv. May 13, 2023 · Is your feature request related to a problem? Please describe. 1198"""1199returnself. If sqlglot can handle this, it will be able to handle any kind of sub-queries, too. import sqlglot. create table test (data String) engine = AggregatingMergeTree() ORDER BY tuple() Feb 12, 2024 · sqlglot. @classmethod. By letting SQLGlot handle the hard part and focusing on preparing the SQL expression, we found a good balance between simplicity and functionality. schema: Database schema. (TABLE this: (IDENTIFIER this: MyTable, quoted: False), db: (IDENTIFIER this: MySchema, quoted Associates this dialect's time formats with their equivalent Python strftime formats. Scope is a good way to do this: from sqlglot import expressions as exp from sqlglot. The optimizer will not simplify expressions like the following if the module cannot be found: Edit on GitHub sqlglot. What is the logic when deciding to make a child expr May 10, 2023 · Traceback (most recent call last): sqlglot. a = z. sqltree is an experimental parser for SQL, providing a syntax tree for SQL queries. It can be used to format SQL or translate between 21 different dialects like DuckDB, Presto / Trino, Spark / Databricks, Snowflake, and BigQuery. Answered by barakalon on Oct 2, 2022. to conform to the target dialect. scope import Scope, build_scope 2 3 4 def eliminate_ctes (expression): 5 """ 6 Remove unused CTEs from an expression. And if you want to remove out column aliases and you might have subqueries, you'd So I decided to write a parser from scratch so that I could actually have a structured understanding of the expressions. dateCooked, SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. sources:A mapping of queries which will be used to continue building lineage. Default: False. transforms import move_ctes_to_top_level 632 633 expression = move_ctes_to_top_level (expression) 634 635 if self. Jan 15, 2024 · We have written a whole branch of regular expressions to achieve this feature since we didn’t know sqlglot at that time. parse_one SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. 1 from __future__ import annotations 2 3 import itertools 4 import typing as t 5 6 from sqlglot import alias, exp 7 from sqlglot. Each SQL variation has its own Dialect subclass, extending the corresponding Tokenizer, Parser and Generator Generator converts a given syntax tree to the corresponding SQL string. source_columns. SQLGlot is a no dependency Python SQL parser, transpiler, optimizer, and engine. columns 256): 257 from sqlglot. dialect. Already looked at Python-sqlparse , sqlparse, but I'm not sure they are up to the You can easily customize the parser, analyze queries, traverse expression trees, and programmatically build SQL. Codes to reproduce: sql = '''create table test ( a int, b string ) partitioned by (dt string) stored as parquet''' sqlglot. I've always struggled with this a little in terms of getting the syntax correct (especially knowing exactly what the syntax should be) Expression) else expression 85 for expression in expressions 86) 87 88 def scan (self, step, context): 89 source = step. expression: Expression to annotate. The args keys of an Expression instance correspond to the arg_types keys of its class. Jan 17, 2023 · Instead of using regular expressions to perform complex replacements, you can use a library such as sqlglot to parse the query into an AST, which you can then update to produce your desired query: Hello, thank you for your work, the library is awesome . a FROM x) CROSS JOIN y") merge_subqueries(expression, leave_tables_isolated=True). source 90 91 if source and isinstance (source, exp. However, it should live noted that SQL validation is cannot SQLGlot’s goal, so some syntax errors mayor go unnoticed. Nov 9, 2023 · Using the DataHub SQL parser. text: The text of the token. Arguments: pretty: Whether to format the produced SQL string. comments: The comments to attach to the token. These expressions can use mathematical and string functions along with basic arithmetic to transform values when the query is executed, as shown in this right now i get following errors: sqlglot. e. There are two binary operations in the above expression: + and = Here's how we reference all the operands in the code below: l r x + 1 = 3 a b. optimizer. Each string in the returned list represents a single transformed SQL Expression: 13 """ 14 Replace references to select aliases in GROUP BY clauses. sql:The SQL string or expression. Uses the Python SQL expression builder and leverages the optimizer/planner to convert SQL into dataframe operations. SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. Dialect() parser: sqlglot. what's after the IN part) and and some others ("implicit columns") that exist in the schema of the pivoted table but don't appear in the AST of the PIVOT operator. 12. Jun 9, 2023 · Instead of fragile regular expressions or direct string replacements, you can use a SQL parser such as sqlglot to make updates to the query when your desired conditions are met: import sqlglot # pip3 install sqlglot. scope import build_scope 6 7 8 def eliminate_subqueries (expression): 9 """ 10 Rewrite derived tables as CTES, deduplicating if possible. . presto import Presto 6 7 8 class Trino (Presto): 9 SUPPORTS_USER_DEFINED_TYPES = False 10 LOG_BASE_FIRST = True 11 12 class Parser (Presto. ENSURE_BOOLS: 636 from sqlglot. annotate_types import annotate_types 169 from sqlglot. The project is in early Alpha, but I'm planning to add helper functions to extract semantic information from expressions as well as have complex transforms of things like CROSS JOIN UNNEST -> LATERAL VIEW EXPLODE. parse_one("WITH y (c) AS (SELECT SUM(a) FROM ( SELECT 1 a ) AS x HAVING c > 0) SELECT c FROM y Oct 13, 2023 · The parse_one function in SQLGlot acts as a keen-eyed interpreter, dissecting a given SQL string and unveiling a syntax tree for the initial parsed SQL statement. For sqlglot, __repr__ calls the to_s method, and __str__ calls the sql method: import sqlglot from sqlglot import expressions as exp table = sqlglot. TableAlias) 255 and not alias. transpile(sql, Dec 12, 2023 · georgesittas commented on Dec 12, 2023. SQLGlot uses dateutil to simplify literal timedelta expressions. ParseError: Invalid expression / Unexpected token. _parse_partition_by() order = self. However, the parser seems to have trouble parsing IF statements (I mainly tried is TSQL, but did not manage to make any other langage parse IF statements). From, sqlglot. Scope has methods for tracing query "sources" to all their columns (see Scope. Normalize all unquoted identifiers to either lower or upper case, dependingon the dialect. expressions as exp source_sql = """ CREATE TABLE IF NOT EXISTS a( a_id uuid NOT NULL, a_test int NOT NULL, CONSTRA Best to not mix types so make sure replacement is the same type as the column. In addition to querying and referencing raw column data with SQL, you can also use expressions to write more complex logic on column values in a query. parse_one ( "select 1 union all select 2 intersect select 1" ) ( UNION this : ( SELECT expressions : ( LITERAL this: 1, is_string: False )), distinct: False, by_name: False, expression : ( INTERSECT this : Jan 13, 2024 · Hey @billstark, I looked into this and it turns out it's rather complicated to solve. This is an experimental feature that is not part of any of the SQL standards but it can be useful when needing to annotate what a selected field is supposed to be. It’s an awesome achievement for the analytics community! I had a question on the expression system logic. Feb 21, 2024 · Constructing a large union of 72 tables in sqlglot hits the stack recursion limit in Python. Arguments: column:The column to build the lineage for. sources. Union'> #855 jerryleooo opened this issue Dec 28, 2022 · 1 comment Comments Expression, dnf: bool = False)-> int: 89 """ 90 The difference in the number of predicates between a given expression and its normalized form. x" ). Suppose we have a query as follows. sql = """. SQL Lesson 9: Queries with expressions. a AND y. The values of the arg_types dict are True if the key is required. Line 9, Col: 1. 1 from __future__ import annotations 2 3 import typing as t 4 5 from sqlglot import expressions as exp 6 7 if t. 3, SQLGlot now supporst DELETE FROM. I would like to know the line number of each expression. Expression]: if not self. expressions. View full answer. We interpret it as a command and parse the rest. Sep 21, 2023 · An approach I was thinking about is using one of many different SQL parser Python packages (sqlparse, sqlglot, sqloxide, ) in order to find the tables and columns (and the structure), and then use one of the SQL query builder Python packages (pypika, python-sql, ) in order to rewrite the query as is, but with aliases. Sep 25, 2023 · Optional Dependencies. @operation (Operation. py module. x xx , 'SOMETHING' yy, from polls p ; """ aliases = [i. 0+, we already use the new SQL lineage parser to generate column-level lineage for BigQuery, Snowflake, Redshift, dbt, Looker, Tableau, PowerBI, Airflow, and a few others. defsimplify_literals(expression, root=True):View Source. the fix for measures seems simple enough: def _parse_match_recognize(self) -> t. parse_one(sql) 12 >>> eliminate_ctes(expression). dialect import (5 approx_count_distinct_sql, 6 arrow_json_extract_sql, 7 build_timestamp_trunc, 8 rename_func, 9 time_format, 1 from sqlglot import exp 2 3 4 def expand_multi_table_selects (expression): 5 """ 6 Replace multiple FROM expressions with JOINs. FROM) Nov 24, 2023 · Hello! I'm using SQLGlot to manual construct expression trees. In this example, the identifier awill not Jun 15, 2023 · sqlglot. List [str]: """. It can be used to format SQL or translate between different dialects like DuckDB, Presto, Spark, Snowflake, and BigQuery. 15 16 Example: 17 >>> from sqlglot import parse_one 18 >>> optimize_joins(parse_one("SELECT * FROM x CROSS JOIN y JOIN z ON x. 161 """ 162 if not offset or len (expressions)!= 1: 163 return expressions 164 165 expression = expressions [0] 166 167 from sqlglot import exp 168 from sqlglot. Jul 2, 2022 · Hi Team, First of all, Thanks for creating an Awesome project, great effort. _match_l_paren() partition = self. expressions] Output: ['xx', 'yy'] In case there are any column selections that do not have an alias, you can retain the expression itself: Mar 2, 2022 · Now got ParseError: Invalid expression / Unexpected token. Some dialects, such as Snowflake, allow you to reference a CTE column alias in the HAVING clause of the CTE. def visit_ast(ast, aliases: Dict[str, str], data_source_id: str): # Base cases if not ast or not isinstance(ast, (Expression, Condition, Literal)): return if isinstance(ast Edit on GitHub sqlglot. The original issue was reported as arising from an in-the-wild data validation use case in Sep 30, 2022 · Ah ok, all clear now. Join)) and \. 15 16 Example: 17 >>> import sqlglot 18 >>> sqlglot. _parse_order() measures = (. sql() 19 'SELECT a AS b FROM x GROUP BY 1' 20 21 Args: 22 expression: the expression that will be transformed. Returns: The expression annotated with types. exp. 561 562 Example: 563 >>> import sqlglot 564 >>> expression = sqlglot. L_PAREN: 'L_PAREN'>, ')': <TokenType. SQLGlot parses SQL into an abstract syntax tree (AST). scope import traverse_scope. values () if isinstance ( source, exp. tokens. Expression: 557 """ 558 Pushes down the CTE alias columns into the projection, 559 560 This step is useful in Snowflake where the CTE alias columns can be referenced in the HAVING. DataType` object. 93 94 Example: 95 >>> import sqlglot 96 >>> expression = sqlglot. May 9, 2024 · Fully reproducible code snippet from sqlglot import parse_one, diff from sqlglot. parser( error_level="CUSTOM" ) errors = [] try Jan 17, 2022 · Basically, this library takes your SQL query and tokenizes it. 1194sql: The original SQL string, used to produce helpful debug messages. If the provided 160 `expressions` argument contains more than one expression, it's returned unaffected. I'm looking for a python (3+) library that would extract the table names that are contained in the from clauses. doris View Source. Contribute to tobymao/sqlglot development by creating an account on GitHub. dialect import (7 Dialect, 8 NormalizationStrategy, 9 arrow_json_extract_sql, 10 date_add_interval_sql, 11 datestrtodate_sql, 12 build_formatted_time, 13 isnull_to_is_null, 14 locate_to Edit on GitHub sqlglot. _match(TokenType. source for scope in traverse_scope ( expression ) for source in scope. I haven't really had a need to parse DELETE and so support is not fully functional. Describe the solution you'd like Ideally, each Expression would have an extra lineno attribute, a bit like what is do . It can be used to format SQL or translate between different dialects like Presto, Spark, and Hive. This essentially makes those identifiers case-insensitive. parse_one("SELECT a FROM (SELECT x. _type_mapping_cache Oct 22, 2021 · i have a complex SQL like below. JSONExtract'>. rc. Syntax errors are highlighted and dialect incompatibilities can warn or raise depending on configurations. Dialect class implements a generic dialect that aims to be as universal as possible. Code to reproduce: import sqlglot def check_syntax( sql: str ): dia = sqlglot. This new way of doing things sets us up for a more sustainable and efficient future in lineage parsing. You can use my library SQLGlot to parse your SQL and extract out the information. 436437Args:438schema_type: the type we want to convert. The choice of SQLglot was an obvious one due to its simple but powerful API, lack of external dependencies and, more importantly, extensive list of supported SQL dialects. ParseError: Required keyword: 'expression' missing for <class 'sqlglot. starrocks View Source. 7 8 Example: SQLGlot. Here is a snippet of code that should help you get started. Build the lineage graph for a column of a SQL query. ParseError: Expected ta Python SQL Parser and Transpiler. I'm mapping a client's database & views & reports, and have dozens of queries to map, so the need to automate the job. 23 24 Returns: 25 The transformed Oct 2, 2022 · 1. Expression]]:1188"""1189Parses a list of tokens and returns a list of syntax trees, one tree1190per parsed SQL statement. dialect:The dialect of input SQL. ast = parse_one(sql_query, read SQLGlot bridges all the different variations, called "dialects", with an extensible SQL transpilation framework. 6. Optional[exp. meta case_sensitive */ FROM table. sql() 19 'SELECT * FROM x JOIN z ON x. It aims to read a wide variety of SQL inputs and output syntactically and semantically correct SQL in the targeted dialects. dialect import rename_func, unit_to_var 7 from sqlglot. helper import find_new_name 5 from sqlglot. qualify_columns import qualify_outputs 258 259 # We keep track of the unaliased column projection indexes instead of the expressions 260 # themselves, because the latter are going to be replaced by new nodes when the aliases 261 # are added and hence we won't be able to Generator converts a given syntax tree to the corresponding SQL string. schema import Schema 11 12 if t. transform(unalias_group). 7 8 Example: 9 >>> import sqlglot 10 >>> sql = "WITH y AS (SELECT a FROM x) SELECT a FROM z" 11 >>> expression = sqlglot. There are some common arg_types keys: "this": This is typically used for the primary child. For example, WITH y (c) AS ( SELECT SUM (a) FROM (SELECT 1 a) AS x HAVING c > 0 ) SELECT c FROM y; 328@classmethod329defget_or_raise(cls With)) 630): 631 from sqlglot. Apr 19, 2024 · from sqlglot import parse_one parse_one ("SELECT x FROM y"). a")). 11951196Returns:1197The list of the produced syntax trees. found_select = False. Line 1, Col: 65. SQLGlot is a no dependency Python SQL parser, transpiler, and optimizer. [. In particular, it seems to be tripped up by the "values" name of the field. scope import build_scope, find_in_scope 4 from sqlglot. 24. 12 def optimize_joins (expression): 13 """ 14 Removes cross joins if possible and reorder joins based on predicate dependencies. parse_one("(a AND b) OR (c AND d)") 97 1 import itertools 2 3 from sqlglot import expressions as exp 4 from sqlglot. 1 from __future__ import annotations 2 3 import typing as t 4 5 from sqlglot import exp 6 from sqlglot. Optional [ErrorLevel] = None, **opts, ) -> t. parse_one("SELECT a AS b FROM x GROUP BY b"). It aims to read a wide variety of SQL inputs and output syntatically correct SQL in the targeted dialects. We finally landed our port of all the ibis backends to sqlglot and we found that the benchmark that tests ibis's ability to construct these huge unions broke. Union [ dict , list , str , float , int , bool , None ] 9 Node = t . SELECT. import sqlparse. schema:The schema of tables. hive import _build_with_ignore_nulls 8 from sqlglot. 440441Returns:442The resulting expression type. expressions as exp. It is kind of complex because there is CTE (Common Table Expression) in it. Dec 28, 2022 · sqlglot. TYPE_CHECKING : 8 JSON = t . Once that is done, you can search for the select query token and parse the underlying tokens. I was impressed with the issue response latency and how frequently sqlglot is released, so I assumed it was included in v6. expression = sqlglot. According to the documentation LIMIT is not a reserved keyword, though it seems like SQLGlot is unable to parse statements referring to a column named limit unless it is escaped. selected_sources and Scope. You can easily customize the parser, analyze queries, traverse expression trees, and programmatically build SQL. helper import seq_get 13 14 15 class StarRocks (MySQL): Ideally sqlglot would not treat the values column reference as a keyword in such cases. errors. The base sqlglot. EDIT: As of v1. It can be used to format SQL or translate between 20 different dialects like DuckDB, Presto / Trino, Spark / Databricks, Snowflake, and BigQuery. Aug 30, 2022 · So a good way to dig into this behavior is to check the __str__ and __repr__ methods of the object. find ( exp. transforms import ensure_bools 637 638 expression = ensure_bools (expression) 639 640 return expression 641 642 def unsupported (self, message: str)-> None: 643 if self May 18, 2023 · The sqlglot library makes this task considerably more straightforward: import sqlglot s = """ select p. Optional[exp. You'd need to remove aliases from sources and rename the tables of columns as you go. 1 from sqlglot. sql() 13 'SELECT a FROM z' 14 15 write: DialectType = None, identity: bool = True, error_level: t. 👍 I see a lot of use cases for this particular library, but they are currently stopped/blocked by the following issue: Any plans to support AT Time Zone for the If leave_tables_isolated is True, this will not merge inner queries into outer queries if it would result in multiple table selects in a single query:. helper import csv_reader, name_sequence 9 from sqlglot. 11 12 Example: 13 >>> import sqlglot 14 >>> expression = sqlglot. However, it should be noted that SQL validation is not SQLGlot’s goal, so some syntax errors may go unnoticed. Line 2, Col: 13. mysql-mimic: Pure-Python implementation of the MySQL server wire protocol arg_types is a class attribute that specifies the possible children. Feb 5, 2023 · This means it starts at the leaves of the query tree. col: The column that the token ends on. In the end, SQLGlot turned out to be a great choice for us. Apr 23, 2024 · My attempt is currently a random attempt and does not help solve the problem; the challenge is being able to access the elements for the expression in the sqlglot AST tree. Syntax errors are highlighted. by sl jl ki qz wj hf cd gs gc