Results of 1 - 10 of about 191 for list (0.006 sec.)
- List Functions 12130
- Function Description list[index] Extracts a single list element using a (1-based) index . list[begin[:end][:step]] Extracts a sublist using slice conventions . Negative values are accepted. list1 && list2 Alias for list_has_any . list1 <->
...list2 Alias for list_distance . list1 <=> list2 Alias for list_cosine_distance . list1 <@ list2 Alias for list_has_all . list1 @> list2 Alias f...or list_has_all . arg1 || arg2 Concatenates two strings, lists, or blobs. Any NULL input results in NULL . See also concat(arg1, a...rg2, ...) and list_concat(list1, list2, ...) . aggregate(list, function_name, ...) Alias for list_aggregate . apply(list, lambda(x)) Alias fo... - https://man.mtool.work/duckdb/2.0/sql/functions/list.html
- Lambda Functions 10462
- DuckDB lambda functions (a.k.a. 'lambdas' or 'lambda expressions') are expressions that define an inline anonymous function. Lambdas are passed as argument to certain list functions , which evaluate the passed lambda expression against its
...elements. The value resulting from the lambda's evaluation is then processed further by the list function to create its return value. Lambdas may also be used in the COLUMNS clause . In that context, the lambda function...column index. The syntax for a lambda expression is: lambda ⟨parameters⟩ : ⟨expression⟩ ⟨parameters⟩ is a comma-separated list of parameter names. Parameters may be given any name, and their name may be referenced in the ⟨expression⟩ . The number of...allowed and required parameters depends on the list function to which it is passed. There is always a mandatory parameter that is used by the list function to pass the curren... - https://man.mtool.work/duckdb/2.0/sql/functions/lambda.html
- Python Client API 9721
- Connection class duckdb. Appender Bases: object append_row ( self , * args ) → None Buffer one row, one value per column, each converted as an executemany parameter would be append_rows ( self , rows : object ) → None Buffer each row of an
...→ _duckdb.DuckDBPyConnection Append the passed DataFrame to the named table appender ( self , table : str , * , columns : list | None = None , action : str = 'insert' , key : list | None = None ) → _duckdb.Appender Create an appender that buffers ro...e Enable profiling for subsequent queries enum_type ( self , name : str , type : _duckdb._sqltypes.DuckDBPyType , values : list ) → _duckdb._sqltypes.DuckDBPyType Create an enum type of underlying ‘type', consisting of the list of ‘values' execute (...meters : object | None = None ) → _duckdb.DuckDBPyConnection Execute the given prepared statement multiple times using the list of parameter sets in parameters extract_statements ( self , query : str ) → list Parse the query string and extract the St... - https://man.mtool.work/duckdb/2.0/clients/python/reference/
- List Type 9155
- A LIST column encodes lists of values. Fields in the column can have values with different lengths, but they must all have the same underlying type. LIST s are typically used to store arrays of numbers, but can contain any uniform data type
..., including other LIST s and STRUCT s. LIST s are similar to PostgreSQL's ARRAY type. DuckDB uses the LIST terminology, but some array_ functions...PostgreSQL compatibility. See the data types overview for a comparison between nested data types. For storing fixed-length lists, DuckDB uses the ARRAY type . Creating Lists Lists can be created using the list_value(expr, ...) function or the equival...ent bracket notation [expr, ...] . The expressions can be constants or arbitrary expressions. To create a list from a table column, use the list aggregate function. List of integers: SELECT [1, 2, 3]; List of strings with a NULL valu... - https://man.mtool.work/duckdb/2.0/sql/data_types/list.html
- Relational API 8773
- The Relational API builds a query one step at a time from Python. A relation, a DuckDBPyRelation , is a piece of SQL text: the methods of the Transformation and Functions sections return a new relation whose text extends the one they were c
...t passed to sql() , such as CREATE TABLE or INSERT , runs at the call, and the relation holds what it returned. The params list or dict is copied when the relation is created, and its values are converted each time the relation runs. A column is also...t , lineterminator is new_line and decimal is decimal_separator . Aliases : from_csv_auto Parameters path_or_buffer : str, list[str], file-like object Path to the file, a glob pattern, a list of paths or a file-like object such as io.StringIO or io.B...delimiter . Detected when omitted. * delimiter : str, keyword-only, default: None Same as sep . * dtype : dict[str, str], list[str], keyword-only, default: None Column types, as a dict of column name to type or a list of types by position; a type is... - https://man.mtool.work/duckdb/2.0/clients/python/relational_api.html
- Unnesting 8686
- 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
...horthand syntax is not available for tuples: tuples can only be unnested using the unnest() function. Calling unnest() The LIST or STRUCT value that is to be unnested is always passed as the first – mandatory – argument to the unnest() function. The...the WHERE or ORDER BY clauses. Since DuckDB 2.0, unnest can be used in the GROUP BY clause . When applied to values of the LIST -type, unnest() may also appear in clauses where one could normally use a table function . Unnesting LIST -Typed Values To...fully understand unnesting LIST -typed values, it is useful to distinguish between the 'input' row that provided the LIST -typed value that is to be unnes... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/unnest.html
- Vectors 8653
- Vectors represent a horizontal slice of a column. They hold a number of values of a specific type, similar to an array. Vectors are the core data representation used in DuckDB. Vectors are typically stored within data chunks . The vector an
...ty mask. The reason for this is that the child elements of a struct can be NULL , but the struct itself can also be NULL . Lists Lists are nested types that contain a single child type, repeated x times per row. Think of them like a variable-length a...rray in C. The way to access list data using vectors is to access the child vector using the duckdb_list_vector_get_child method. The duckdb_vector_get_data...must be used to get the offsets and lengths of the lists stored as duckdb_list_entry , that can then be applied to the child vector. typedef struct { uint64_t offset; uint64_t le... - https://man.mtool.work/duckdb/2.0/clients/c/vector.html
- Execution Format 8653
- Vector is the container format used to store in-memory data during execution. DataChunk is a collection of Vectors, used for instance to represent a column list in a PhysicalProjection operator. Data Flow DuckDB uses a vectorized query exec
...ows for a more compressed representation, and potentially allows for compressed execution throughout the system. Below the list of supported vector formats is shown. Flat Vectors Flat vectors are physically stored as a contiguous array, this is the s...the value once. SELECT lst || 'duckdb' FROM range(1000) tbl(lst); Since duckdb is a string literal, the value of the literal is the same for every row. In a flat vector, we would have to duplicate the literal duckdb once for every row. The constant v...as an early out (when the prefix does not match, we know the strings are not equal and don't need to chase any pointers). List Vectors List vectors are stored as a series of list entries together with a child Vector. The child vector contains the va... - https://man.mtool.work/duckdb/2.0/internals/vector.html
- Aggregate Functions 7705
- Examples Produce a single row containing the sum of the amount column: SELECT sum(amount) FROM sales; Produce one row per unique region, containing the sum of amount for each group: SELECT region, sum(amount) FROM sales GROUP BY region; Ret
...region is north using the FILTER clause : SELECT sum(amount), sum(amount) FILTER (region != 'north') FROM sales; Returns a list of all regions in order of the amount column: SELECT list(region ORDER BY amount DESC) FROM sales; Returns the amount of t..., there are some order-sensitive aggregates that can have non-deterministic results without ordering, e.g., first , last , list and string_agg / group_concat / listagg . These can be made deterministic by ordering the arguments. For example: CREATE T...C) AS countdown FROM tbl; countdown 3, 2, 1 Handling NULL Values All general aggregate functions ignore NULL s, except for list ( array_agg ), first ( arbitrary ) and last . To exclude NULL s from list , use a FILTER clause that excludes rows with nu... - https://man.mtool.work/duckdb/2.0/sql/functions/aggregates.html
- Array Type 7672
- 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
...nd STRUCT types. Arrays can be used to store vectors such as word embeddings or image embeddings. To store variable-length lists, use the LIST type . See the data types overview for a comparison between nested data types. The ARRAY type in PostgreSQL...ction . Construct with the array_value function: SELECT array_value(1, 2, 3); You can always implicitly cast an array to a list (and use list functions, like list_extract , [i] ): SELECT array_value(1, 2, 3)[2]; You can cast from a list to an array (...rom Arrays Retrieving one or more values from an array can be accomplished using brackets and slicing notation, or through list functions like list_extract and array_extract . Using the example in Defining an Array Field . The following queries for e... - https://man.mtool.work/duckdb/2.0/sql/data_types/array.html
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