Results of 1 - 10 of about 19 for Identifiers (0.003 sec.)
- Keywords and Identifiers 15231
- Identifiers Similarly to other SQL dialects and programming languages, identifiers in DuckDB's SQL are subject to several rules. Unquoted identifiers need to conform to a number of rules: They must not be a reserved keyword (see duckdb_keyw
...l character, e.g., SELECT 123 AS 1col is invalid. They cannot contain whitespaces (including tabs and newline characters). Identifiers can be quoted using double-quote characters ( " ). Quoted identifiers can use any keyword, whitespace or special character..., e.g., "SELECT" and " § ? ¶ " are valid identifiers. Double quotes can be escaped by repeating the quote character, e.g., to create an identifier named IDENTIFIER "X" , use "...IDENTIFIER ""X""" . New As of DuckDB 2.0, identifiers can also be quoted using backtick characters ( ` ), following exactly the same rules as double-quoted identifiers. A backt... - https://man.mtool.work/duckdb/2.0/sql/dialect/keywords_and_identifiers.html
- PostgreSQL Compatibility 10637
- DuckDB's SQL dialect closely follows the conventions of the PostgreSQL dialect. The few exceptions to this are listed on this page. Floating-Point Arithmetic DuckDB and PostgreSQL handle floating-point arithmetic differently for division by
...ue true 1 = 1.1 false false true = 'true' true true true = 1 error true 'true' = 1 error error Case Sensitivity for Quoted Identifiers PostgreSQL is case-insensitive. The way PostgreSQL achieves case insensitivity is by lowercasing unquoted identifiers with...TaBLe (x INTEGER); SELECT * FROM "MyTaBLe"; ERROR: relation "MyTaBLe" does not exist PostgreSQL does not only treat quoted identifiers as case-sensitive; it treats all identifiers as case-sensitive, e.g., this also does not work: CREATE TABLE "PreservedCase...OR: relation "preservedcase" does not exist Therefore, case-insensitivity in PostgreSQL only works if you never use quoted identifiers with different cases. For DuckDB, this behavior was problematic when interfacing with other tools (e.g., Parquet, Pandas)... - https://man.mtool.work/duckdb/2.0/sql/dialect/postgresql_compatibility.html
- SELECT Statement 8810
- The SELECT statement retrieves rows from the database. Examples Select all columns from the table tbl : SELECT * FROM tbl; Select the rows from tbl : SELECT j FROM tbl WHERE i = 3; Perform an aggregate grouped by the column i : SELECT i, su
...t of values that is supplied instead of a SELECT statement. Row IDs For each table, the rowid pseudocolumn returns the row identifiers based on the physical storage. CREATE TABLE t (id INTEGER, content VARCHAR); INSERT INTO t VALUES (42, 'hello'), (43, 'wor...ld'); SELECT rowid, id, content FROM t; rowid id content 0 42 hello 1 43 world In the current storage, these identifiers are contiguous unsigned integers (0, 1, ...) if no rows were deleted. Deletions introduce gaps in the rowids which may be...d 1 3 5 7 9 The rowid values are stable within a transaction. Bestpractice It is strongly advised to avoid using rowids as identifiers. If there is a user-defined column named rowid , it shadows the rowid pseudocolumn. Common Table Expressions Full Syntax D... - https://man.mtool.work/duckdb/2.0/sql/statements/select.html
- Geometry Data Type 8349
- Name Description GEOMETRY Geospatial entity The GEOMETRY data type is used to store and manipulate geometric objects, such as points, lines, and polygons. The GEOMETRY type was part of the spatial extension but became a built-in data type i
...of type GEOMETRY('OGC:CRS84') stores geometries that are associated with the "OGC CRS84" coordinate reference system. CRS identifiers in DuckDB are always strings. OGC:CRS84 is the identifier for a common geographic coordinate system spanning the whole glo...n older storage version fails with an error such as Invalid Input Error: GEOMETRY columns with coordinate reference system identifiers are not supported in storage versions prior v1.5.0 . Create or attach the database with ATTACH 'file.db' (STORAGE_VERSION...option to true to simply skip any unknown CRSs and create GEOMETRY columns without CRS instead. -- Ignore any unknown CRS identifiers SET ignore_unknown_crs = true; select 'POINT(1 2)'::GEOMETRY('DUCK:1337') AS my_point; ---- ┌─────────────┐ │ my_point │ │... - https://man.mtool.work/duckdb/2.0/sql/data_types/geometry.html
- Numeric Types 8349
- Fixed-Width Integer Types The types TINYINT , SMALLINT , INTEGER , BIGINT and HUGEINT store whole numbers, that is, numbers without fractional components, of various ranges. Attempts to store values outside of the allowed range will result
.... For example: SELECT sqrt(2) > '-inf', 'nan' > sqrt(2); (sqrt(2) > '-inf') ('nan' > sqrt(2)) true true Universally Unique Identifiers ( UUID s) DuckDB supports universally unique identifiers (UUIDs) through the UUID type. These use 128 bits and are represe...e dashes). For example, 4ac7a9e9-607c-4c8a-84f3-843f0191e3fd is a valid UUID. DuckDB supports generating UUIDv4 and UUIDv7 identifiers. To retrieve the version of a UUID value, use the uuid_extract_version function . UUIDv4 To generate a UUIDv4 value, use t... - https://man.mtool.work/duckdb/2.0/sql/data_types/numeric.html
- Create Synthetic Data 8230
- DuckDB lets you quickly generate synthetic datasets by combining a few building blocks: functions and clauses that generate rows , functions that generate values to fill those rows, and extensions that generate whole benchmark datasets. Thi
...ange: SELECT (random() * 100)::INTEGER AS score FROM range(3); UUIDs Several utility functions generate universally unique identifiers, which make good synthetic primary keys: uuid() and its alias uuidv4() generate random (version 4) UUIDs, uuidv7() generat...sh , md5 and sha256 turn a row number into a deterministic pseudo-random value, which is useful when you want reproducible identifiers: SELECT hash(i) AS id, md5(i::VARCHAR) AS token FROM range(3) t(i); Repeating Strings repeat(string, count) builds a strin... - https://man.mtool.work/duckdb/2.0/guides/snippets/create_synthetic_data.html
- Friendly SQL 8179
- DuckDB offers several advanced SQL features and syntactic sugar to make SQL queries more concise. We refer to these colloquially as “friendly SQL”. Several of these features were first introduced by DuckDB, while some are inspired by other
...S in the anchor part of common table expressions SWITCH statements as syntactic sugar for the CASE expression Literals and Identifiers Case-insensitivity while maintaining case of entities in the catalog Deduplicating identifiers Underscores as digit separa... - https://man.mtool.work/duckdb/2.0/sql/dialect/friendly_sql.html
- ATTACH and DETACH Statements 8008
- DuckDB allows attaching to and detaching from database files. Examples Attach the database file.db with the alias inferred from the name ( file ): ATTACH 'file.db'; Attach the database file.db with an explicit alias ( file_db ): ATTACH 'fil
...build them from variables , environment variables or string concatenation. This keeps credentials and environment-specific identifiers, such as account numbers, out of your SQL scripts. Read the database path from a variable: SET VARIABLE db_path = 'file.db...m catalog, the temporary catalog and the initially attached database together with the main schema. Also note the rules on identifiers and database names in particular . Default Database and Schema When a table is created without any qualifications, the tab... - https://man.mtool.work/duckdb/2.0/sql/statements/attach.html
- SQL Introduction 7940
- This page provides an overview of how to perform simple operations in SQL. This tutorial is only intended to give you an introduction and is in no way a complete tutorial on SQL. This tutorial is adapted from the PostgreSQL tutorial . DuckD
...introduce comments. Whatever follows them is ignored up to the end of the line. SQL is case-insensitive about keywords and identifiers. When returning identifiers, their original cases are preserved . In the SQL command, we first specify the type of command... - https://man.mtool.work/duckdb/2.0/sql/introduction.html
- SET VARIABLE and RESET VARIABLE Statements 7940
- DuckDB supports the definition of SQL-level variables using the SET VARIABLE and RESET VARIABLE statements. Variable Scopes DuckDB supports two levels of variable scopes: Scope Description SESSION Variables with a SESSION scope are local to
...ywhere an expression is allowed: SET VARIABLE my_var = 30; SELECT 20 + $my_var AS total; Variable names that are not valid identifiers can be quoted, for example $"my var" . If SET VARIABLE is invoked on an existing variable, it will overwrite its value: SE... - https://man.mtool.work/duckdb/2.0/sql/statements/set_variable.html
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