Sqlglot examples It’s pure Python, and other advanced SQL constructs. It can be used to format SQL or translate between 23 different dialects like DuckDB, Presto / Trino, Spark / Databricks, Snowflake, and BigQuery. For all my examples in this article, I will use the alias sg for the library sqlglot, as we need to use several different functions in this package. max_: stop early if count exceeds this. 6. The answer is from the column INNER_COL1 from the table S1. expand_alias_refs: Whether to expand references to aliases. You switched accounts on another tab or window. SQLGlot \n. \n Python macros can return either strings or SQLGlot expressions that SQLMesh incorporates into the query’s semantic representation. parse_one(sql) 26 >>> pushdown_projections . pip3 install "sqlglot[rs]" Then, in our Python code, we should import the library before use. Sign in Product For example, date/time functions vary from dialects and can be hard to deal with. {"payload":{"allShortcutsEnabled":false,"fileTree":{"docs":{"items":[{"name":"sqlglot","path":"docs/sqlglot","contentType":"directory"},{"name":"CNAME","path":"docs I want to convert SQL keywords to lowercase when I transpile SQL with sqlglot. For example, the query I provided at the beginning of this section can have the following AST representation: Figure 1: Abstract Syntax Tree derived from a SQL query. 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. helper import seq_get, ensure_list 17 from You signed in with another tab or window. sample-sql SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. recipeID = rc. parser View Source. a + 1 + 1 AS c FROM x' 20 21 What is SQLGlot ? Quick Start Guide GH https://github. Would you be interested in making the code examples in the docs interactive for better understanding? Here is what it could look like: Try SQLGlot in Y minutes. find_all And a special thanks to Krisztián Szűcs for his work on the internal representation and SQLGlot refactor work, it has drastically improved the Ibis codebase. fill_from_start: Indicates that if None values should be inserted at the start or end of the list. expand_stars: Whether to expand star queries. The package can be used to format SQL or translate between 19 different dialects like DuckDB, Presto, Spark, Snowflake, and BigQuery. This AST can be used to standardize queries or provide the foundations for implementing an actual engine. b = y. Commented Sep 9, However, it should be noted that SQL validation is not SQLGlot’s goal, so some syntax errors may go unnoticed. parse_one(sql) 12 >>> eliminate_ctes(expression). sql() 13 'SELECT a FROM z' 14 15 Expression: 9 """ 10 Expand lateral column alias references. – Gregg Lind. parse 1 import itertools 2 3 from sqlglot import expressions as exp 4 from sqlglot. def(2 * days) to select * from table where date > {@abc. In this post, we will explore an approach to building a Directed Acyclic Graph (DAG) from Common Table For SQL parsing we use a fork of SQLGlot. The example I gave originally was that a user might want to access other sheets in an excel file, but users can also use the table() function to provide a schema. min_num_words: The minimum number of words that are going to be in the result. a")). name, i. htmlResources What Is a SQL Dial Arguments: expression: Expression to qualify. expressions as exp sql = """ SELECT rc. PREFIX: value is a prefix of a keyword in trie; TrieResult. Which Components Form an End-to-End Data Stack? For it to be a complete data stack, we need to integrate data from its source systems, transform, aggregate, and clean data, and ultimately serve and visualize it, solving the core An easily customizable SQL parser and transpiler SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. You can find a complete source code in the diff. 1 from __future__ import annotations 2 3 import datetime 4 import logging 5 import functools 6 import itertools 7 import typing as t 8 from collections import deque, defaultdict 9 from functools import reduce 10 11 import sqlglot 12 from sqlglot import Dialect, exp 13 from sqlglot. Examples. It aims to read a wide variety of SQL inputs and output syntactically and semantically correct SQL in the targeted dialects. 29 30 Example: 31 >>> import sqlglot 32 >>> schema = {"tbl": {"col": "INT"}} 33 >>> expression = sqlglot. This is straightforward in the above example, but in more complex examples, I find it difficult to know exactly what this syntax should be (and I don't think there's an automatic way of going from the tree to the equivalent code to create it). FAILED: the search was unsuccessful; TrieResult. 26 27 This transformation reflects how identifiers would be resolved by the engine corresponding 28 to each 1 from sqlglot import exp 2 from sqlglot. Returns: The normalization distance. 11 Convert correlated or Rewrite sqlglot AST to merge derived tables into the outer query. transpile("SELECT EPOCH_MS(1618088028295)", read= "duckdb", write= "hive")[0]) In my use case, I often want to use this as a template, but make small chanegs to the arguments (quoted, table, this). dialects. dialect: The dialect to parse catalog and schema into. SQLGlot is a no dependency Python SQL parser, transpiler, and optimizer. Additionally, it exposes a number of helper functions, which are mainly used to programmatically build SQL For all my examples in this article, I will use the alias sg for the library sqlglot, as we need to use several different functions in this package. helper import apply_index_offset, ensure_list, seq_get 10 from sqlglot. 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 Please check your connection, disable any ad blockers, or try using a different browser. Transpilation using sqlglot Transpilation using sqlglot Table of contents 1. The PATCHversion is incremented when there are backwards-compatible fixes or feature additions. In order to avoid creating countless AST nodes to represent these different traits, SQLGlot chooses to define a standardized AST which unifies similar concepts across dialects. py file in the project’s macros directory. Example: SELECT a, b, c FROM some_table should be converted to select a, b, c from some_table I have I have found that there is normalize and normalize_functions options in sqlglot. schema: The schema of tables. MINOR. We dealt with SQLGlot's problem of not handling columns that didn’t exist in the SQL expression. parse_one ("SELECT a FROM (SELECT x. With this refactor, Fetch the zones example data with the For example, the browser runs the code from Craigslist from 1995, and it's only possible to this day because HTML is declarative. 843 844 There are also dialects like Spark, which are case-insensitive even when quotes are 845 present, and dialects like MySQL, whose resolution rules match those employed by the 846 underlying operating system, for example sqlglot is a Python package that serves as a comprehensive SQL parser, transpiler, optimizer, and engine. DataType type of a column in the schema. Docs Sign up. With SQLGlot, you can take a SQL query targeting a warehouse such as Snowflake and seamlessly run it in CI on mock Python data. Skip to content. b" 16 >>> expression = sqlglot. 12 def optimize_joins (expression): 13 """ 14 Removes cross joins if possible and reorder joins based on predicate dependencies. SQLglot is a fantastic tool for exploring SQL Abstract Syntax Trees (ASTs) across various dialects. parse_one(sql) 18 >>> expand_laterals(expression). transform(unalias_group). For example, consider this query: CREATE VIEW Build the lineage graph for a column of a SQL query. 9 10 Example: 11 >>> import sqlglot 12 >>> expression = sqlglot. Part 2: Creating ER Diagram from SQL Query Part 3: SQL-to-Diagram with DDL Part 4: Query Interpretation, understanding complex SQL. It's easy to mock data and create arbitrary UDFs Imagine having a tool that can dissect queries and fish out the goodies — the columns, aliases, and tables from your query. xyz(yyyy)} For the If it was quoted, it'd need to be treated as case-sensitive, 842 and so any normalization would be prohibited in order to avoid "breaking" the identifier. a AS a FROM (SELECT x. Arguments: trie: The trie to be searched. 23 24 Returns: 25 The converted time string. g. optimizer. normalize import normalized 3 from sqlglot. This also merges CTEs if they are selected from only once. executor. Default: False, i. SQLGlot helps translate SQL from one dialect to another, ensuring compatibility with your target platform. It can be used to format SQL or translate between 24 different dialects like DuckDB, Presto / Trino, Spark / Databricks, Snowflake, and BigQuery. 2 There are other examples as well. 1 while trying to reproduce: sql = """ sql-metadata is a Python library that uses a tokenized query returned by python-sqlparse and generates query metadata. SQLGlot allows us to write common parsing and transformation logic over dialect-agnostic expressions. ingredient FROM recipeCooked rc INNER JOIN recipe r ON r. It aims to read a wide variety of SQL inputs and output syntatically correct SQL in the targeted dialects. It can be used to format SQL or translate between 21 different dialects like DuckDB, Presto / Trino, Spark / Databricks, Snowflake, and BigQuery. import sqlglot as SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. You signed out in another tab or window. dnf: Whether to check if the expression is in Disjunctive Normal Form (DNF). trim_selects: Whether or not to clean up SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. For example, if we had a query like SELECT * FROM table WHERE foo = bar, we knew foo and bar were columns in table. 21 22 Example: 23 >>> import sqlglot 24 >>> sql = "SELECT y. scope import (5 Scope as Scope, 6 build_scope as build_scope, 7 find_all_in_scope as find_all_in_scope, 8 find_in_scope as find_in_scope, 9 traverse_scope 1 from sqlglot import exp 2 3 4 def lower_identities (expression): 5 """ 6 Convert all unquoted identifiers to lower case. Navigation Menu Toggle navigation. I had a task that involved building a dependency graph by statically analyzing the relationship of MySQL views. Most dialects provide a function to do this, a sample of which is shown below: Edit on GitHub sqlglot. a + 1 AS b, x. That’s where SQLGlot shines. It is designed to read a wide variety of SQL inputs and output syntactically and semantically correct SQL in the targeted dialects. transpile(), but they only lowercase identifiers and function names. Arguments: value: The value to be split. 7 8 Assuming the schema is all lower case, this essentially makes identifiers case-insensitive. We will use SQLGlot to parse SQL queries containing CTEs and extract the necessary information to build the DAG. 1 from __future__ import annotations 2 3 import logging 4 import typing as t 5 from collections import defaultdict 6 7 from sqlglot import exp 8 from sqlglot. 5 def expand_multi_table_selects (expression): 6 """ 7 Replace multiple FROM expressions with JOINs. ` text_table ` ( schema => ' inline=(col1 date properties {`drill. transpile ("SELECT EPOCH_MS(1618088028295) Wanted to give sqlglot a shoutout as it saved me a ton of time. Let’s explore how you can use SQLGlot to transpile SQL between dialects while creating a data model. Let’s connect on LinkedIn or Twitter. It is currently the fastest pure-Python SQL parser. User-provided SQL is interpolated into these dialect-agnostic SQL statements 3. parse_one 7 def eliminate_joins (expression): 8 """ 9 Remove unused joins from an expression. It can be used to format SQL or translate between different dialects like Presto, Spark, and Hive. TrieResult. a + 1 AS b, b + 1 AS c FROM x" 17 >>> expression = sqlglot. by respecting 25 case-sensitivity). scope import build_scope, find_in_scope 4 from sqlglot. EXISTS: key exists in trie 👋 Hi, I’m Poom, founder at Datascale — building SQL+Metadata modeling tool!. tsql View Source. It can be used to format SQL or translate between 20 different dialects like DuckDB, Presto / Trino, Spark / Databricks, Snowflake, and BigQuery. This example shows the sqlglot. SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. Below is an example: 1 from sqlglot import exp 2 from sqlglot. sql() 35 'SELECT tbl. 15 16 Example: 17 >>> from sqlglot import parse_one 18 >>> optimize_joins(parse_one("SELECT * FROM x CROSS JOIN y JOIN z ON x. 22 trie: optional trie, can be passed in for performance. SQLGlot can rewrite queries into an "optimized" form. helper import name_sequence 3 from sqlglot. → Data health monitoring / data observability: Analysing database SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. | Restackio. hive import Hive 16 from sqlglot. db: Default database name for tables. exp. 137 138 Example: 139 >>> import sqlglot 140 >>> sqlglot. get_query_columns("SELECT test, id FROM foo, bar") [u'test', u'id'] >>> For example when a nested query is refactored into a common table expression (CTE), this kind of change doesn’t have any functional impact on either a query or its outcome. Strings used as pre/post-statements or return values in Python-based models will be parsed into SQLGlot expressions, which means that SQLMesh will still be able to understand them semantically and thus provide information such as column-level lineage. For example, let's take the conversion of strings to timestamps. catalog: Default catalog name for tables. You can rate examples to help us improve the quality of examples. a AS a, x. They are defined in a . parse_one("SELECT a AS b FROM x GROUP BY b"). b AS b FROM x) AS y" 25 >>> expression = sqlglot. dialect import (7 binary_from_function, 8 build_formatted_time, 9 is_parse_json, 10 pivot_column_names, 11 rename_func, 12 trim_sql, 13 unit_to_str, 14) 15 from sqlglot. 3. sql() 12 'SELECT * FROM x CROSS JOIN y' 13 """ 14 for from_ in expression. a = z. Restack. import sqlglot print (sqlglot. 7 8 Example: 9 >>> import sqlglot 10 >>> sql = "WITH y AS (SELECT a FROM x) SELECT a FROM z" 11 >>> expression = sqlglot. col AS col FROM tbl' 36 37 Args: 38 expression: Expression to qualify Arguments: expression: Expression to qualify db: Database name catalog: Catalog name schema: A schema to populate infer_csv_schemas: Whether to scan READ_CSV calls in order to infer the CSVs' schemas. import sqlglot sqlglot. pip3 install sqlglot Python SQL Parser and Transpiler. parse_one('SELECT Bar. Given a version number MAJOR. Python SQL Parser and Transpiler. Arguments: table: the source table. It can theoretically be used to trace back SQLGlot is a powerful tool for analyzing and transforming SQL, but the learning curve can be intimidating. parse 1 from sqlglot. It can be used to format SQL or translate between 24 different dialects like DuckDB, The example below showcases the execution of a query that involves aggregations and joins: Get the sqlglot. scope import Scope, build_scope 2 3 4 def eliminate_ctes (expression): 5 """ 6 Remove unused CTEs from an expression. time import Pyparsing is a good tool for this, with lots of examples of parsing sql around. errors import ErrorLevel, ParseError, concat_messages, merge_errors 9 from sqlglot. import sqlglot import sqlglot. 9 10 Convert scalar subqueries into cross joins. One could also define this model by simply returning a string that contained the SQL query of the SQL-based example. This post is intended to familiarize newbies with SQLGlot's abstract syntax trees, SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. column: the target column. We came up with a solution. 12 13 Example: 14 >>> import sqlglot 15 >>> sql = "SELECT x. PATCH, SQLGlot uses the following versioning strategy: 1. Core data linking algorithms are Splink 2. normalize: whether to normalize identifiers according to the dialect of interest. Here are a couple of example from the sql-metadata github readme: >>> sql_metadata. scope import ScopeType, find_in_scope, traverse_scope 4 5 6 def unnest_subqueries (expression): 7 """ 8 Rewrite sqlglot AST to convert some predicates with subqueries into joins. How does it compare to other tools? Sqlparse relies on regex and is very slow and inaccurate. scope import build_scope 6 7 8 def eliminate_subqueries (expression): 9 """ 10 Rewrite derived tables as CTES, deduplicating if possible. format` = `yyyy-MM-dd`}) properties {`drill. Python parse_one - 19 examples found. Even though it is a fairly realistic starting point, we strongly encourage the reader to study existing dialect implementations in order to understand how their various components can be modified, depending on the use-case. key: The target key. These are the top rated real world Python examples of sqlglot. a FROM x) CROSS JOIN y") >>> merge_subqueries (expression). . def expand_multi_table_selects (expression): View Source. sql() 19 'SELECT x. dialect: The dialect of input SQL. Here is a snippet of code that should help you get started. Example: >>> import sqlglot >>> expression = sqlglot. If you're interested, I'll be happy to send you a PR. Returns: A pair (value, subtrie), where subtrie is the sub-trie we get at the point where the search stops, and value is a TrieResult value that can be one of:. Arguments: expression: The expression to compute the normalization distance for. Contribute to th368/sqlglot-levenshtein development by creating an account on GitHub. Numbers Station works with many different data warehouses, all of which use slightly different syntax. 15 16 Examples: 17 >>> format_time("%Y", {"%Y": "YYYY"}) 18 'YYYY' 19 20 Args: 21 mapping: dictionary of time format to target time format. We surveyed a lot of SQL parsers and found that SQLGlot was best suited for our needs. Bar') 13 >>> lower I know the README says "best effort" to preserve comments, but we've seen some odd behavior with sqlmesh format silently removing comments in some cases. For example, to find all nodes that correspond to the order\_id field in the previous AST, you can use the following code: nodes = ast. SQLGlot’s ability to parse SQL into an abstract syntax tree (AST) is not just a technical feat; Below example for identifying functions on columns in filters which is bad in snowflake; One of SQLMesh’s most powerful features is its integration with SQLGlot, a Python-based SQL transpiler. def(2 * days). Expression: 135 """ 136 Replace references to select aliases in GROUP BY clauses. parse_one("SELECT a FROM (SELECT a FROM x) AS y") logger = <Logger sqlglot (WARNING)> TRAVERSABLES = Python SQL Parser and Transpiler. It can be used to format SQL or translate between 21 different dialects like DuckDB, Presto / Trino, SQLGlot is a lightweight and fast SQL parser that supports various SQL dialects. It can be used to format SQL or translate between 24 different dialects like DuckDB, Presto / Trino, Spark / This module contains the implementation of all supported Expression types. NEQ. we check if it's in Conjunctive Normal Form (CNF). sql() 141 'SELECT a AS b FROM x GROUP BY 1' 142 143 Args: 144 expression: the expression that will be transformed. Reload to refresh your session. While SQLGlot’s documentation is extremely thorough, we want to share a few practical examples of how we use SQLGlot in our codebase. parse_one("SELECT col FROM tbl") 34 >>> qualify_columns(expression, schema). Returns: The resulting column type. recipeID LEFT OUTER JOIN SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. helper import first, merge_ranges, while_changing SQLGlot’s TokenType enum provides an indirection layer between lexemes and their types. The implementation discussed in this post is now a part of the SQLGlot library. tmp . Create the following python script to check translation of datafunctions from duckdb to hive. sep: The value to use to split on. Perform a split on a value and return N words as a result with None used for words that don't exist. As an added benefit, I've also fixed some examples that failed due to import errors. This metadata can return column and table names from your supplied SQL query. 1 # ruff: noqa: F401 2 3 from sqlglot. sql: The SQL string or expression. dialect: the SQL dialect that will be used to parse table if it's a string. Concept Overview. helper import find_new_name 5 from sqlglot. Returns: The Using the Python library sqlglot, where can I find documentation that explains: Which attributes I should expect to find on which expression nodes types (which arg types does Join, For example, what documentation could I look at to know that code like below We figured out which columns were in the tables by looking at the expression. dateCooked, r. To give an example of what can be done with SQLGlot, I’ll share a CI test that I created to stop people from using ‘SELECT *’ when reading from a table/view. 505 506 Examples: 507 >>> import sqlglot 508 >>> expression = sqlglot. 145 146 Returns: 147 Expression: 27 """ 28 Rewrite sqlglot AST to have fully qualified columns. SELECT * FROM table( dfs . Can I 18 def pushdown_projections (expression, schema = None, remove_unused_selections = True): 19 """ 20 Rewrite sqlglot AST to remove unused columns projections. schema: Schema to infer column names and types. To illustrate - sqlglot can't disambiguate columns in this query without knowing the schema: unqualified = """ SELECT a, b, FROM physical_table JOIN (SELECT * FROM physical Edit on GitHub sqlglot. com/sqlglot. b FROM y) AS y ON x. com/tobymao/sqlglot?tab=readme-ov-fileDocs https://sqlglot. See more Our aim here is to understand various use cases of SQL parsing (outside of database engine) and explore how SQLGlot can help. I'v tried to use build_scope() for AST of update statement, but it detect wrong query based on unbalanced quotes or wrong quotes placement or column filtered values having wrong quotes Example: "select * python; mysql; validation; sql SQLGlot is a no-dependency SQL parser, transpiler, optimizer, and engine. sources: A mapping of queries which will be used to continue building lineage. Contribute to web-logs2/sqlglot-10 development by creating an account on GitHub. a AND TRUE JOIN y ON y SQLGlot supports annotations in the sql expression. 8 9 Example: 10 >>> from sqlglot import parse_one 11 >>> expand_multi_table_selects(parse_one("SELECT * FROM x, y")). Optional [str]: 13 """ 14 Converts a time string given a mapping. 21 def normalize_identifiers (expression, dialect = None): 22 """ 23 Normalize identifiers by converting them to either lower or upper case, 24 ensuring the semantics are preserved in each case (e. sqltree is an experimental parser for SQL, providing a syntax tree for SQL queries. sql() 19 'SELECT * FROM x JOIN z ON x. For example: For example: Lets say I want to find the source table for the 'COL1' at the final select. 11 12 This assumes `qualify_columns` as already run. 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. a FROM x CROSS JOIN y' I want to achieve the following sql query conversion using sqlglot select * from table where date > abc. 2. For example, != and <> are often used interchangeably to represent "not equals", so SQLGlot groups them together by mapping them both to TokenType. Arguments: column: The column to build the lineage for. If you want to run my examples, please don’t forget to run the line of code below. Here's one example I found in sqlglot==25. SQLGlot’s main purpose is to parse an input SQL query written in any of the 19 (at the time of writing) supported dialects and produce a tree-like data structure like the one above. find\_all('Field', value='order\_id') The above example demonstrates how certain parts of the base Dialect class can be overridden to match a different specification. TABLE1. It can be used to format SQL or translate between 20 different dialects like DuckDB, Presto, Spark, Snowflake, and BigQuery. Initially, I was using sqlparse to extract the dependencies from the SQL statements, but it required me to create an increasingly hacky recursive function. This is a necessary step for most of the optimizer's rules to work; do not set to Edit on GitHub sqlglot. Here’s a simple example of how to use SQLGlot to parse and generate SQL queries: import sqlglot # Parsing a SQL query query = "SELECT * FROM users WHERE age > 30" parsed = sqlglot. \n. e. 10 11 This only removes joins when we know that the join condition doesn't produce duplicate rows. optimizer import RULES as RULES, optimize as optimize 4 from sqlglot. Returns a list because a generator could result in 504 incomplete properties which is confusing. parse_one extracted from open source projects. 1 from __future__ import annotations 2 3 import datetime 4 import re 5 import typing as t 6 from functools import partial, reduce 7 8 from sqlglot import exp, generator, parser, tokens, transforms 9 from sqlglot. a FROM x LEFT JOIN (SELECT DISTINCT y. optimizer View Source. SQLGlot - Pure Python SQL Parser and Transpiler Intermediate Showcase https: For example, you may have a query that you want to run in both Presto and Spark, but they have different data types and UDF names / signatures. Backends can implement transpilation and You can use my library SQLGlot to parse your SQL and extract out the information. dialect import (10 Dialect, 11 NormalizationStrategy, 12 any_value_to_max_sql, 13 date_delta_sql, 14 datestrtodate_sql, Edit on GitHub sqlglot. strict` = `false`} ' )) Explore Python Sqlglot for efficient SQL query generation and management in AI asset workflows. 11 12 Example: 13 >>> import sqlglot 14 >>> expression = sqlglot. py module. a AND y. It performs a variety of techniques to create a new canonical AST. 13 14 Example: 15 >>> import sqlglot 16 >>> sql = "SELECT x. python API documentation generator 1 from __future__ import annotations 2 3 import typing as t 4 5 from sqlglot import exp, transforms 6 from sqlglot. 26 """ 27 if not string: 28 return None 29 30 start = 0 31 end = 1 32 size I want to get source tables and their columns from update statement by using sqlglot. sql 'SELECT x. scope: A pre-created scope to use instead. A AS A FROM "Foo". The MINORversion is incremented when there are backwards-incompatible fixes or feature additions. Contribute to tobymao/sqlglot development by creating an account on GitHub. simplify View Source. bqqqy ojky sacfy spwx lltbrum jko smrzrj rfvxr vlvnlc pwrtva