DuckDBUtils

Repository(db::DuckDB.DB)

Construct a Repository object that holds a DuckDB.DB as well as a pool of connections.

Use DBInterface.execute(f::Base.Callable, repository::Repository, sql::AbstractString, [params]) to run a function on the result of a query sql on an available connection in the pool.

get_catalog(repository::Repository; schema = nothing)

Extract the catalog of available tables from a Repository repository.

acquire_connection(repository::Repository)

Acquire an open connection to the database repository.db from the pool repository.pool. See also release_connection.

release_connection(repository::Repository, con)

Release connection con to the pool repository.pool

with_connection(f, repository::Repository, [N])

Acquire a connection con from the pool repository.pool. Then, execute f(con) and release the connection to the pool. An optional parameter N can be passed to determine the number of connections to be acquired (defaults to 1).

render_params(catalog::SQLCatalog, node::SQLNode, params = (;))

Return query string and parameter list from query expressed as node.

to_sql(x)

Convert a julia value x to its SQL representation.

load_table(
    repository::Repository,
    table,
    name::AbstractString;
    schema = nothing
)

Load a Julia table table as name in schema schema in repository.db.

replace_table(
    repository::Repository,
    query::Union{AbstractString, SQLNode}
    [params,]
    name::AbstractString;
    schema = nothing,
    virtual::Bool = false
)

Replace table name in schema schema in repository.db with the result of a given query with optional parameters params.

Use virtual = true to replace a view instead of a table.

export_table(
    repository::Repository,
    query::Union{AbstractString, SQLNode}
    [params,]
    path::AbstractString;
    schema = nothing,
    options...
)

Export to path (with options options) the result of a given query with optional parameters params in schema schema in repository.db.

delete_table(
    repository::Repository,
    name::AbstractString;
    schema = nothing,
    virtual::Bool = false
)

Delete table name in schema schema in repository.db.

Use virtual = true to delete a view instead of a table.

with_table(f, repository::Repository, table; schema = nothing)

Register a table under a random unique name name, apply f(name), and then unregister the table.

colnames(repository::Repository, table::AbstractString; schema = nothing)

Return list of columns for a given table.

Batches(tbl, batchsize::Integer, nrows::Integer)

Construct a Batches iterator based on a table tbl with nrows in total. The resulting object iterates column-based tables with batchsize rows each.

_numobs(cols)

Compute the number of rows of a column-based table cols.

_init(schm::Tables.Schema)

Initialize an empty table with schema schm.

_append!(batch::AbstractDict, cols, rg = Colon())

Append rows rg of column-based table cols to the dict table batch.

in_schema(name::AbstractString, schema::Union{AbstractString, Nothing})

Utility to create a name to refer to a table within the schema.

For instance

julia> print(in_schema("tbl", nothing))
"tbl"
julia> print(in_schema("tbl", "schm"))
"schm"."tbl"