Results of 1 - 10 of about 21 for Structs (0.004 sec.)
- Struct Data Type 14393
- Conceptually, a STRUCT column contains an ordered list of columns called “entries”. The entries are referenced by name using strings. This document refers to those entry names as keys. Each row in the STRUCT column must have the same keys.
...the schema . Each row in a STRUCT column must have the same layout. The names of the struct entries are case-insensitive. STRUCT s are typically used to nest multiple columns into a single column, and the nested column can be of any type, including oth...er STRUCT s and LIST s. STRUCT s are similar to PostgreSQL's ROW type. The key difference is that DuckDB STRUCT s require the same ke...rformance by fully utilizing its vectorized execution engine, and also enforces type consistency for improved correctness. Structs with unnamed entries are represented by the TUPLE type , which can be created using the row function or the (expr, ...) no... - https://man.mtool.work/duckdb/2.0/sql/data_types/struct.html
- Typecasting 11095
- Typecasting is an operation that converts a value in one particular data type to the closest corresponding value in another data type. Like other SQL engines, DuckDB supports both implicit and explicit typecasting. Explicit Casting Explicit
...e implicitly cast to lists of the same type. For example, an INTEGER[3] array can be implicitly cast to an INTEGER[] list. Structs Structs can be cast to other structs as long as they share at least one field. The rationale behind this requirement is to...help avoid unintended errors. If two structs do not have any fields in common, then the cast was likely not intended. SELECT CAST({'a': 42} AS STRUCT(a VARCHAR)); Fiel...ames of the struct can also be in a different order. The fields of the struct will be reshuffled based on the names of the structs. SELECT CAST({'a': 42, 'b': 84} AS STRUCT(b VARCHAR, a VARCHAR)); For combination casting , the fields of the resulting st... - https://man.mtool.work/duckdb/2.0/sql/data_types/typecasting.html
- Unnesting 10469
- Unnesting is an operation that decomposes values of a composite types into its components. Values of the LIST and STRUCT type may be unnested using the unnest() function . Unnesting turns a LIST -typed value into a table column: each list-e
..., 3]); Unnesting a struct, generating two columns (a, b): SELECT unnest({'a': 42, 'b': 84}); Recursive unnest of a list of structs: SELECT unnest([{'a': 42, 'b': 84}, {'a': 100, 'b': NULL}], recursive := true); Limit depth of recursive unnest using max_...nger than the other, the shorter list is padded with NULL values. Empty and NULL lists both unnest to zero rows. Unnesting Structs Unnesting a struct, generating two columns (a, b): SELECT unnest({'a': 42, 'b': 84}); Unnesting a struct, generating two c...recursively, generating 5 rows (1, 2, 3, 4, 5): SELECT unnest([[1, 2, 3], [4, 5]], recursive := true); Unnesting a list of structs recursively, generating two rows of two columns (a, b): SELECT unnest([{'a': 42, 'b': 84}, {'a': 100, 'b': NULL}], recursi... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/unnest.html
- Struct Functions 10266
- The functions on this page work on STRUCT values . Functions that access entries by position, such as struct[idx] , struct_extract_at , struct_contains , struct_position and struct_values , also accept TUPLE values , i.e., structs with unna
...med entries. struct_concat accepts either only STRUCT s or only TUPLE s. Functions that work with entry names, i.e., struct_insert , struct_keys , struct_update and remap_struct..., require a STRUCT . Name Description struct.entry Dot notation that serves as an alias for struct_extract from named STRUCT s. struct[entry] Bracket notation that serves as an alias for struct_extract from named STRUCT s. struct[idx] Bracket notat...pes, and filling missing fields from defaults . row(any, ...) Create a TUPLE containing the argument values. struct_concat(structs...) Merge the multiple structs into a single STRUCT . struct_contains(struct, entry) Check if the STRUCT contains the spec... - https://man.mtool.work/duckdb/2.0/sql/functions/struct.html
- Star Expression 8287
- Syntax The * expression can be used in a SELECT statement to select all columns that are projected in the FROM clause. SELECT * FROM tbl; TABLE.* and STRUCT.* The * expression can be prepended by a table name to select only columns from tha
...ust handle any potential struct keys. See the STRUCT data type and STRUCT functions pages for more details on working with structs. For example: SELECT st.* FROM (SELECT {'x': 1, 'y': 2, 'z': 3} AS st); x y z 1 2 3 EXCLUDE Clause EXCLUDE allows you to e...ust handle any potential struct keys. See the STRUCT data type and STRUCT functions pages for more details on working with structs. For example: SELECT st.* FROM (SELECT {'x': 1, 'y': 2, 'z': 3} AS st); x y z 1 2 3... - https://man.mtool.work/duckdb/2.0/sql/expressions/star.html
- Regular Expressions 8084
- DuckDB offers pattern matching operators ( LIKE , SIMILAR TO , GLOB ), as well as support for regular expressions via functions. Regular Expression Syntax DuckDB uses the RE2 library as its regular expression engine. For the regular express
..., name_list[, options]) Finds non-overlapping occurrences of regex in string and returns the capturing groups as a list of structs with corresponding names from name_list . regexp_full_match(string, regex[, options]) Returns true if the entire string ma...tions]) | Description | Finds non-overlapping occurrences of regex in string and returns the capturing groups as a list of structs with corresponding names from name_list . A set of optional options can be set. | | Example | regexp_extract_all('Peter: 3... - https://man.mtool.work/duckdb/2.0/sql/functions/regular_expressions.html
- Types 7983
- DuckDB is a strongly typed database system. As such, every column has a single type specified. This type is constant over the entire column. That is to say, a column that is labeled as an INTEGER column will only contain INTEGER values. Duc
...For example, it is possible to define an array of integers ( INTEGER[] ). It is also possible to define types as arbitrary structs ( ROW(i INTEGER, j VARCHAR) ). For that reason, native DuckDB type objects are not mere enums, but a class that can potent...pe ). For most primitive types, e.g., integers or varchars, the enum is sufficient. For more complex types, such as lists, structs or decimals, the logical type must be used. typedef enum DUCKDB_TYPE { DUCKDB_TYPE_INVALID = 0, DUCKDB_TYPE_BOOLEAN = 1, D...om a DuckDB result. For example, the duckdb_value functions do not support structural reading of composite types (lists or structs) or more complex types like enums or decimals. For more information about data chunks, see the documentation on data chunk... - https://man.mtool.work/duckdb/2.0/clients/c/types.html
- Writing Tests 7881
- Development and Testing It is crucial that any new features that get added have correct tests that not only test the “happy path”, but also test edge cases and incorrect usage of the feature. In this section, we describe how DuckDB tests ar
...──┬──────────────────────┐ │ bool │ tinyint │ smallint │ int │ bigint │ hugeint │ … │ struct │ struct_of_arrays │ array_of_structs │ map │ union │ │ boolean │ int8 │ int16 │ int32 │ int64 │ int128 │ │ struct(a integer, … │ struct(a integer[]… │ struct(a... - https://man.mtool.work/duckdb/2.0/dev/sqllogictest/writing_tests.html
- Array Type 7881
- An ARRAY column stores fixed-sized arrays. All fields in the column must have the same length and the same underlying type. Arrays are typically used to store arrays of numbers, but can contain any uniform data type, including ARRAY , LIST
...ER[3]; Arrays can be nested: SELECT array_value(array_value(1, 2), array_value(3, 4), array_value(5, 6)); Arrays can store structs: SELECT array_value({'a': 1, 'b': 2}, {'a': 3, 'b': 4}); Defining an Array Field Arrays can be created using the ⟨TYPE_NAM... - https://man.mtool.work/duckdb/2.0/sql/data_types/array.html
- Map Type 7881
- MAP s are similar to STRUCT s in that they are an ordered list of key-value pairs. However, MAP s do not need to have the same keys present for each row, and thus are suitable for use cases where the schema is unknown beforehand or varies p
...INT is valid). MAP s may not have duplicate keys. MAP s return NULL if a key is not found rather than throwing an error as structs do. In contrast, STRUCT s must have string keys, but each value may have a different type. See the data types overview for... - https://man.mtool.work/duckdb/2.0/sql/data_types/map.html
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