| DBTable_v9 | R Documentation |
A comprehensive database table management class that provides high-level operations for data manipulation, schema validation, and table administration. This class combines database connectivity with data validation and efficient bulk operations.
The DBTable_v9 class is a sophisticated database table abstraction that provides:
Core functionality:
Table creation and schema management
Data insertion with bulk loading capabilities
Upsert operations (insert or update)
Index management (creation, deletion)
Data validation through customizable validators
Integration with dplyr for data queries
Advanced features:
Automatic table creation based on field specifications
Schema validation with custom validator functions
Efficient bulk data loading using database-specific methods
Index optimization for query performance
Cross-database compatibility (SQL Server, PostgreSQL)
Data validation: The class supports custom validation functions for both field types and data contents, ensuring data integrity and schema compliance.
dbconnectionDatabase connection.
dbconfigConfiguration details of the database.
table_nameName of the table in the database.
table_name_short_for_mssql_fully_specified_for_postgresFully specified name of the table in the database (e.g. \[db\].\[dbo\].\[table_name\]).
table_name_short_for_mssql_fully_specified_for_postgres_textFully specified name of the table in the database (e.g. \[db\].\[dbo\].\[table_name\]).
table_name_fully_specifiedFully specified name of the table in the database (e.g. \[db\].\[dbo\].\[table_name\]).
table_name_fully_specified_textFully specified name of the table in the database (e.g. \[db\].\[dbo\].\[table_name\]) as a text string.
field_typesThe types of each column in the database table (INTEGER, DOUBLE, TEXT, BOOLEAN, DATE, DATETIME).
field_types_with_lengthThe same as field_types but with (100) added to the end of all TEXT fields.
keysThe combination of variables that uniquely identify each row in the database.
keys_with_lengthThe same as keys but with (100) added to the end of all TEXT fields.
indexesA named list of vectors (generally "ind1", "ind2", etc.) that improves the speed of data retrieval operations on a database table.
validator_field_contentsA function that validates the data before it is inserted into the database.
load_folderA temporary folder that is used to write data to before inserting into the database.
censorsA named list of censors.
new()Create a new DBTable_v9 object.
DBTable_v9$new( dbconfig, table_name, field_types, keys, indexes = NULL, validator_field_types = validator_field_types_blank, validator_field_contents = validator_field_contents_blank )
dbconfigConfiguration details of the database (driver, server, port, db, schema, user, password, trusted_connection, sslmode, role_create_table).
table_nameName of the table in the database.
field_typesThe types of each column in the database table (INTEGER, DOUBLE, TEXT, BOOLEAN, DATE, DATETIME).
keysThe combination of these variables uniquely identifies each row of data in the table.
indexesA named list of vectors (generally "ind1", "ind2", etc.) that improves the speed of data retrieval operations on a database table.
validator_field_typesA function that validates the field_types before the DB schema is created.
validator_field_contentsA function that validates the data before it is inserted into the database.
A new 'DBTable_v9' object.
print()Class-specific print function.
DBTable_v9$print(...)
...Not in use.
connect()Connect from the database
DBTable_v9$connect()
disconnect()Disconnect from the database
DBTable_v9$disconnect()
table_exists()Does the table exist
DBTable_v9$table_exists()
create_table()Create the database table
DBTable_v9$create_table()
remove_table()Drop the database table
DBTable_v9$remove_table()
insert_data()Inserts data
DBTable_v9$insert_data( newdata, confirm_insert_via_nrow = FALSE, verbose = TRUE )
newdataThe data to insert.
confirm_insert_via_nrowChecks nrow() before insert and after insert. If nrow() has not increased sufficiently, then attempt an upsert.
verboseBoolean. Inserts data into the database table
upsert_data()Upserts data into the database table
DBTable_v9$upsert_data( newdata, drop_indexes = names(self$indexes), verbose = TRUE )
newdataThe data to insert.
drop_indexesA vector containing the indexes to be dropped before upserting (can increase performance).
verboseBoolean.
drop_all_rows()Drops all rows in the database table
DBTable_v9$drop_all_rows()
drop_rows_where()Drops rows in the database table according to the SQL condition.
DBTable_v9$drop_rows_where(condition)
conditionSQL text condition.
keep_rows_where()Keeps rows in the database table according to the SQL condition.
DBTable_v9$keep_rows_where(condition)
conditionSQL text condition.
drop_all_rows_and_then_upsert_data()Drops all rows in the database table and then upserts data.
DBTable_v9$drop_all_rows_and_then_upsert_data( newdata, drop_indexes = names(self$indexes), verbose = TRUE )
newdataThe data to insert.
drop_indexesA vector containing the indexes to be dropped before upserting (can increase performance).
verboseBoolean.
drop_all_rows_and_then_insert_data()Drops all rows in the database table and then inserts data.
DBTable_v9$drop_all_rows_and_then_insert_data( newdata, confirm_insert_via_nrow = FALSE, verbose = TRUE )
newdataThe data to insert.
confirm_insert_via_nrowChecks nrow() before insert and after insert. If nrow() has not increased sufficiently, then attempt an upsert.
verboseBoolean.
tbl()Provides access to the database table via dplyr::tbl.
DBTable_v9$tbl()
print_dplyr_select()Prints a template dplyr::select call that you can easily copy/paste for all your variables.
DBTable_v9$print_dplyr_select()
add_indexes()Adds indexes to the database table from 'self$indexes'
DBTable_v9$add_indexes()
drop_indexes()Drops all indees from the database table
DBTable_v9$drop_indexes()
confirm_indexes()Confirms that the names and number of indexes in the database are the same as in the R code. Does not confirm the contents of the indexes!
DBTable_v9$confirm_indexes()
nrow()Gets the number of rows in the database table
DBTable_v9$nrow(use_count = FALSE)
use_countIf true, then uses the count command, which is slow but accurate. If false, then uses summary statistics, which is fast but inaccurate.
info()Gets the information about the database table
DBTable_v9$info()
clone()The objects of this class are cloneable with this method.
DBTable_v9$clone(deep = FALSE)
deepWhether to make a deep clone.
## Not run:
# Create database connection
db_config <- list(
driver = "ODBC Driver 17 for SQL Server",
server = "localhost",
db = "mydb",
user = "myuser",
password = "mypass"
)
# Define table schema
field_types <- c(
"id" = "INTEGER",
"name" = "TEXT",
"value" = "DOUBLE",
"date_created" = "DATE"
)
# Create table object
my_table <- DBTable_v9$new(
dbconfig = db_config,
table_name = "my_data_table",
field_types = field_types,
keys = c("id"),
validator_field_types = validator_field_types_blank,
validator_field_contents = validator_field_contents_blank
)
# Create table in database
my_table$create_table()
# Insert data
sample_data <- data.frame(
id = 1:3,
name = c("Alice", "Bob", "Charlie"),
value = c(10.5, 20.3, 15.7),
date_created = as.Date("2023-01-01")
)
my_table$insert_data(sample_data)
# Query data using dplyr
result <- my_table$tbl() |>
dplyr::filter(value > 15) |>
dplyr::collect()
# Add indexes for performance
my_table$add_indexes(c("name", "date_created"))
# Upsert (insert or update) data
new_data <- data.frame(
id = 2:4,
name = c("Bob_Updated", "Charlie", "David"),
value = c(25.0, 15.7, 30.2),
date_created = as.Date("2023-01-02")
)
my_table$upsert_data(new_data)
## End(Not run)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.