Results of 1 - 10 of about 12 for parent (0.004 sec.)
- Subqueries 12876
- Subqueries are parenthesized query expressions that appear as part of a larger, outer query. Subqueries are usually based on SELECT ... FROM , but in DuckDB other query constructs such as PIVOT can also appear as a subquery. Scalar Subquery
...have been uncorrelated subqueries, where the subqueries themselves are entirely self-contained and can be run without the parent query. There exists a second type of subqueries called correlated subqueries. For correlated subqueries, the subquery uses...values from the parent subquery. Conceptually, the subqueries are run once for every single row in the parent query. Perhaps a simple way of envi...suppose that we want to find the minimum grade for every course. We could do that as follows: SELECT * FROM grades grades_parent WHERE grade = (SELECT min(grade) FROM grades WHERE grades.course = grades_parent.course); grade course 7 Math 8 CS The sub... - https://man.mtool.work/duckdb/2.0/sql/expressions/subqueries.html
- Unnesting 11231
- 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
...hen explicitly passing false , recursion is disabled. In that case, other additional parameters such as max_depth and keep_parent_names are effectively ignored max_depth : UINT32 , default: 1 . This controls how many levels of recursion should at most...e applied. Values greater than 1 imply recursion, and in such cases recursive need not be explicitly passed as true . keep_parent_names : BOOLEAN , default: false . Whether to create column names using the keys of all ancestor members. This argument is...M (VALUES ([1, 2, 3]), ([4, 5])) tbl(l); x index 1 1 2 2 3 3 4 1 5 2 Keep Column Names When Recursively Unnesting The keep_parent_names parameter can be used to retain the parent column names when recursively unnesting a named struct. For example, unne... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/unnest.html
- JSON Processing Functions 10948
- JSON Extraction Functions There are two extraction functions, which have their respective operators. The operators can only be used if the string is stored as the JSON logical type. These functions support the same two location notations as
...tracts, has a low precedence as it is also used in lambda functions . Therefore, you need to surround the -> operator with parentheses when expressing operations such as equality comparisons ( = ). For example: SELECT ((JSON '{"field": 42}')->'field')...ators bind more tightly than AND and OR , so an extraction can be combined with other conditions in a WHERE clause without parentheses: SELECT count(*) FROM (VALUES ('{}'::JSON)) t(j) WHERE 1 = 1 AND j->>'field' IS NOT NULL; Warning DuckDB's JSON data...element. The resulting table has the following columns: Field Type Description key VARCHAR Key of element relative to its parent value JSON Value of element type VARCHAR json_type (function) of this element atom JSON json_value (function) of this elem... - https://man.mtool.work/duckdb/2.0/data/json/json_functions.html
- Vectors 8896
- 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
...id of the logical type can then be obtained using duckdb_get_type_id . Vectors themselves do not have sizes. Instead, the parent data chunk has a size (that can be obtained through duckdb_data_chunk_get_size ). All vectors that belong to a data chunk...es) duckdb_list_vector_get_child Retrieves the child vector of a list vector. The resulting vector is valid as long as the parent vector is valid. Syntax duckdb_vector duckdb_list_vector_get_child ( duckdb_vector vector ); Parameters vector : The vecto...duckdb_struct_vector_get_child Retrieves the child vector of a struct vector. The resulting vector is valid as long as the parent vector is valid. Syntax duckdb_vector duckdb_struct_vector_get_child ( duckdb_vector vector , idx_t index ); Parameters ve... - https://man.mtool.work/duckdb/2.0/clients/c/vector.html
- DuckDB_% Metadata Functions 8472
- DuckDB offers a collection of table functions that provide metadata about the current database. These functions reside in the main schema and their names are prefixed with duckdb_ . The resultset returned by a duckdb_ table function may be
...set elsewhere in the statement, for example in the WHERE clause. Table functions are still functions, and you should write parentheses after the function name to call it to obtain its returned resultset: SELECT * FROM duckdb_settings(); Alternatively,...you may execute table functions also using the CALL -syntax: CALL duckdb_settings(); In this case too, the parentheses are mandatory. For some of the duckdb_% functions, there is also an identically named view available, which also resi...e, while filtering out those objects that are marked as internal. We mention it here, because if you accidentally omit the parentheses in your duckdb_ table function call, you might still get a result, but from the identically named view. Example: The... - https://man.mtool.work/duckdb/2.0/sql/meta/duckdb_table_functions.html
- Star Expression 8348
- 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
...ber 1 10 2 20 3 NULL Unpacking a COLUMNS Expression By wrapping a COLUMNS expression in UNPACK , the columns expand into a parent expression, much like the iterable unpacking behavior in Python . Without UNPACK , operations on the COLUMNS expression ar...(SELECT NULL a, 42 b, true c); result result result NULL 42 true With UNPACK , the COLUMNS expression is expanded into its parent expression, coalesce in the example above, which results in a single column: SELECT coalesce(UNPACK(COLUMNS(['a', 'b', 'c'... - https://man.mtool.work/duckdb/2.0/sql/expressions/star.html
- Typecasting 8207
- 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
..._cast_implicitly function . Combination Casting When values of different types need to be combined to an unspecified joint parent type, the system will perform implicit casts to an automatically selected parent type. For example, list_value(1::INT64, 1... - https://man.mtool.work/duckdb/2.0/sql/data_types/typecasting.html
- Securing Extensions 7658
- DuckDB has a powerful extension mechanism, which has the same privileges as the user running DuckDB's (parent) process. This introduces security considerations. Therefore, we recommend reviewing the configuration options listed on this page
... - https://man.mtool.work/duckdb/2.0/operations_manual/securing_duckdb/securing_ext...
- Complete API 7375
- This page contains the reference for DuckDB's C API. The reference contains several deprecation notices. These concern methods whose long-term availability is not guaranteed as they may be removed in the future. That said, DuckDB's develope
...es) duckdb_list_vector_get_child Retrieves the child vector of a list vector. The resulting vector is valid as long as the parent vector is valid. Syntax duckdb_vector duckdb_list_vector_get_child ( duckdb_vector vector ); Parameters vector : The vecto...duckdb_struct_vector_get_child Retrieves the child vector of a struct vector. The resulting vector is valid as long as the parent vector is valid. Syntax duckdb_vector duckdb_struct_vector_get_child ( duckdb_vector vector , idx_t index ); Parameters ve...duckdb_array_vector_get_child Retrieves the child vector of an array vector. The resulting vector is valid as long as the parent vector is valid. The resulting vector has the size of the parent vector multiplied by the array size. Syntax duckdb_vector... - https://man.mtool.work/duckdb/2.0/clients/c/api.html
- R-Tree Indexes 7375
- The spatial extension provides support for spatial indexing through the R-tree extension index type. Why Should I Use an R-Tree Index? When working with geospatial datasets, it is very common that you want to filter rows based on their spat
...mn intersect a specific region of interest, as you can skip searching entire sub-trees if the bounding rectangles of their parent nodes don't intersect the query region at all. Once the leaf nodes are reached, only the specific rows whose geometries in...index, simply use the CREATE INDEX statement with the USING RTREE clause, passing the geometry column to index within the parentheses. For example: -- Create a table with a geometry column CREATE TABLE my_table (geom GEOMETRY); -- Create an R-tree ind... - https://man.mtool.work/duckdb/2.0/core_extensions/spatial/r-tree_indexes.html
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