read_sql

Execute a database query and cache it locally as a Feather file and remotely as a Parquet file. Cache storage locations are managed by tessilake.depths options. Database connection defined by an ODBC profile with the name set by the tessilake.tessitura option.

Usage

read_sql(
  query,
  name = digest::sha1(query),
  select = NULL,
  primary_keys = NULL,
  date_column = NULL,
  freshness = as.difftime(7, units = "days"),
  incremental = TRUE,
  ...
)

read_sql_table(
  table_name,
  schema = "dbo",
  select = NULL,
  primary_keys = NULL,
  date_column = NULL,
  freshness = as.difftime(7, units = "days"),
  incremental = TRUE,
  ...
)

Arguments

query

character query to run on the database.

name

name of the query, defaults to the SHA1 hash of the query.

select

vector of strings indicating columns to select from database

primary_keys

character vector, primary keys of the table. read_sql_table will attempt to identify the primary keys using SQL metadata.

date_column

character, date column of the table showing the last date the row was updated. Defaults to "last_update_dt" if it exists in the table.

freshness

the returned data will be at least this fresh

incremental

whether or not to load data incrementally, default is TRUE

...

Arguments passed on to write_cache

table_name

character, table name without schema.

schema

character, database schema. Default is dbo

Value

an Apache arrow::Table

an Apache arrow::Table.

Functions

• read_sql_table(): Reads a table or view from a SQL database and caches it locally using read_sql.

Examples

if (FALSE) { # \dontrun{
read_sql("select * from T_CUSTOMER", "t_customer",
  primary_keys = "customer_no",
  date_column = "last_update_dt"
)
} # }
if (FALSE) { # \dontrun{
read_sql_table("T_CUSTOMER")
} # }