Load statements in GoogleSQL
LOAD DATA statement
Loads data from one or more files into a table. The statement can create a new
table, append data into an existing table or partition, or overwrite an existing
table or partition. If the LOAD DATA statement fails, the table into which you
are loading data remains unchanged.
Syntax
LOAD DATA {OVERWRITE|INTO} [{TEMP|TEMPORARY} TABLE]
[[project_name.]dataset_name.]table_name
[(
column_list
)]
[[OVERWRITE] PARTITIONS (partition_column_name=partition_value)]
[PARTITION BY partition_expression]
[CLUSTER BY clustering_column_list]
[OPTIONS (table_option_list)]
FROM FILES(load_option_list)
[WITH PARTITION COLUMNS
[(partition_column_list)]
]
[WITH CONNECTION connection_name]
column_list: column[, ...]
partition_column_list: partition_column_name, partition_column_type[, ...]
Arguments
INTO: If a table with this name already exists, the statement appends data to the table. You must useINTOinstead ofOVERWRITEif your statement includes thePARTITIONSclause.OVERWRITE: If a table with this name already exists, the statement overwrites the table.{TEMP|TEMPORARY} TABLE: Use this clause to create or write to a temporary table.project_name: The name of the project for the table. The value defaults to the project that runs this DDL query.dataset_name: The name of the dataset for the table.table_name: The name of the table.column_list: Contains the table's schema information as a list of table columns. For more information about table schemas, see Specifying a schema. If you don't specify a schema, BigQuery uses schema auto-detection to infer the schema.When you load hive-partitioned data into a new table or overwrite an existing table, then that table schema contains the hive-partitioned columns and the columns in the
column_list.If you append hive-partitioned data to an existing table, then the hive-partitioned columns and
column_listcan be a subset of the existing columns. If the combined list of columns in not a subset of the existing columns, then the following rules apply:If your data is self-describing, such as ORC, PARQUET, or AVRO, then columns in the source file that are omitted from the
column_listare ignored. Columns in thecolumn_listthat don't exist in the source file are written withNULLvalues. If a column is in thecolumn_listand the source file, then their types must match.If your data is not self-describing, such as CSV or JSON, then columns in the source file that are omitted from the
column_listare only ignored if you setignore_unknown_valuestoTRUE. Otherwise this statement returns an error. You can't list columns in thecolumn_listthat don't exist in the source file.
[OVERWRITE] PARTITIONS: Use this clause to write to or overwrite exactly one partition. When you use this clause, the statement must begin withLOAD DATA INTO.partition_column_name: The name of the partitioned column to write to. If you use both thePARTITIONSand thePARTITION BYclauses, then the column names must match.partition_value: Thepartition_idof the partition to append or overwrite. To find thepartition_idvalues of a table, query theINFORMATION_SCHEMA.PARTITIONSview. You can't set thepartition_valueto__NULL__or__UNPARTITIONED__. You can only append to or overwrite one partition. If your data contains values that belong to multiple partitions, then the statement fails with an error. Thispartition_valuemust be literal value.partition_expression: Specifies the table partitioning when creating a new table.clustering_column_list: Specifies table clustering when creating a new table. The value is a comma-separated list of column names, with up to four columns.table_option_list: Specifies options for creating the table. If you include this clause and the table already exists, then the options must match the existing table specification.partition_column_list: A list of external partitioning columns.connection_name: The connection name that is used to read the source files from an external data source.load_option_list: Specifies options for loading the data.
If no table exists with the specified name, then the statement creates a new
table. If a table already exists with the specified name, then the behavior
depends on the INTO or OVERWRITE keyword. The INTO keyword appends the
data to the table, and the OVERWRITE keyword overwrites the table.
If your external data uses a
hive-partitioned layout,
then include the WITH PARTITION COLUMNS clause. If you include the WITH
PARTITION COLUMNS clause without partition_column_list, then
BigQuery infers the partitioning from the data layout. If you
include both column_list and WITH PARTITION COLUMNS, then
partition_column_list is required.
You can't use the LOAD DATA statement to load data into a temporary table.
column
(column_name column_schema[, ...]) contains the table's
schema information in a comma-separated list.
column := column_name column_schema column_schema := { simple_type | STRUCT<field_list> | ARRAY<array_element_schema> } [PRIMARY KEY NOT ENFORCED | REFERENCES table_name(column_name) NOT ENFORCED] [DEFAULT default_expression] [NOT NULL] [OPTIONS(column_option_list)] simple_type := { data_type | STRING COLLATE collate_specification } field_list := field_name column_schema [, ...] array_element_schema := { simple_type | STRUCT<field_list> } [NOT NULL]
column_nameis the name of the column. A column name:- Must contain only letters (a-z, A-Z), numbers (0-9), or underscores (_)
- Must start with a letter or underscore
- Can be up to 300 characters
column_schema: Similar to a data type, but supports an optionalNOT NULLconstraint for types other thanARRAY.column_schemaalso supports options on top-level columns andSTRUCTfields.column_schemacan be used only in the column definition list ofCREATE TABLEstatements. It cannot be used as a type in expressions.simple_type: Any supported data type aside fromSTRUCTandARRAY.If
simple_typeis aSTRING, it supports an additional clause for collation, which defines how a resultingSTRINGcan be compared and sorted. The syntax looks like this:STRING COLLATE collate_specificationIf you have
DEFAULT COLLATE collate_specificationassigned to the table, the collation specification for a column overrides the specification for the table.default_expression: The default value assigned to the column.field_list: Represents the fields in a struct.field_name: The name of the struct field. Struct field names have the same restrictions as column names.NOT NULL: When theNOT NULLconstraint is present for a column or field, the column or field is created withREQUIREDmode. Conversely, when theNOT NULLconstraint is absent, the column or field is created withNULLABLEmode.Columns and fields of
ARRAYtype do not support theNOT NULLmodifier. For example, acolumn_schemaofARRAY<INT64> NOT NULLis invalid, sinceARRAYcolumns haveREPEATEDmode and can be empty but cannot beNULL. An array element in a table can never beNULL, regardless of whether theNOT NULLconstraint is specified. For example,ARRAY<INT64>is equivalent toARRAY<INT64 NOT NULL>.The
NOT NULLattribute of a table'scolumn_schemadoes not propagate through queries over the table. If tableTcontains a column declared asx INT64 NOT NULL, for example,CREATE TABLE dataset.newtable AS SELECT x FROM Tcreates a table nameddataset.newtablein whichxisNULLABLE.
column_option_list
Specify a column option list in the following format:
NAME=VALUE, ...
NAME and VALUE must be one of the following combinations:
NAME |
VALUE |
Details |
|---|---|---|
description |
|
Example: This property is equivalent to the schema.fields[].description table resource property. |
rounding_mode |
|
Example: This specifies the rounding mode
that's used for values written to a
This property is equivalent to the
|
data_policies |
ARRAY<STRING> |
Applies a data policy to a column in a table (Preview). Example: The Example: |
VALUE is a constant expression containing only literals, query parameters,
and scalar functions.
The constant expression cannot contain:
- A reference to a table
- Subqueries or SQL statements such as
SELECT,CREATE, orUPDATE - User-defined functions, aggregate functions, or analytic functions
- The following scalar functions:
ARRAY_TO_STRINGREPLACEREGEXP_REPLACERANDFORMATLPADRPADREPEATSESSION_USERGENERATE_ARRAYGENERATE_DATE_ARRAY
Setting the VALUE replaces the existing value of that option for the column, if
there was one. Setting the VALUE to NULL clears the column's value for that
option.
partition_expression
PARTITION BY is an optional clause that controls
table and
vector index partitioning.
partition_expression is an expression that determines how to partition the
table or vector index. The partition expression can contain the following
values:
_PARTITIONDATE. Partition by ingestion time with daily partitions. This syntax cannot be used with theAS query_statementclause.DATE(_PARTITIONTIME). Equivalent to_PARTITIONDATE. This syntax cannot be used with theAS query_statementclause.<date_column>. Partition by aDATEcolumn with daily partitions.DATE({ <timestamp_column> | <datetime_column> }). Partition by aTIMESTAMPorDATETIMEcolumn with daily partitions.DATETIME_TRUNC(<datetime_column>, { DAY | HOUR | MONTH | YEAR }). Partition by aDATETIMEcolumn with the specified partitioning type.TIMESTAMP_TRUNC(<timestamp_column>, { DAY | HOUR | MONTH | YEAR }). Partition by aTIMESTAMPcolumn with the specified partitioning type.TIMESTAMP_TRUNC(_PARTITIONTIME, { DAY | HOUR | MONTH | YEAR }). Partition by ingestion time with the specified partitioning type. This syntax cannot be used with theAS query_statementclause.DATE_TRUNC(<date_column>, { MONTH | YEAR }). Partition by aDATEcolumn with the specified partitioning type.RANGE_BUCKET(<int64_column>, GENERATE_ARRAY(<start>, <end>[, <interval>])). Partition by an integer column with the specified range, where:startis the start of range partitioning, inclusive.endis the end of range partitioning, exclusive.intervalis the width of each range within the partition. Defaults to 1.
table_option_list
The option list lets you set table options such as a label and an expiration time. You can include multiple options using a comma-separated list.
Specify a table option list in the following format:
NAME=VALUE, ...
NAME and VALUE must be one of the following combinations:
NAME |
VALUE |
Details |
|---|---|---|
expiration_timestamp |
TIMESTAMP |
Example: This property is equivalent to the expirationTime table resource property. |
partition_expiration_days |
|
Example: Sets the partition expiration in days. For more information, see Set the partition expiration. By default, partitions don't expire. This property is equivalent to the timePartitioning.expirationMs table resource property but uses days instead of milliseconds. One day is equivalent to 86400000 milliseconds, or 24 hours. This property can only be set if the table is partitioned. |
require_partition_filter |
|
Example: Specifies whether queries on this table must include a a predicate
filter that filters on the partitioning column. For more information,
see
Set partition filter requirements. The default value is
This property is equivalent to the timePartitioning.requirePartitionFilter table resource property. This property can only be set if the table is partitioned. |
friendly_name |
|
Example: This property is equivalent to the friendlyName table resource property. |
description |
|
Example: This property is equivalent to the description table resource property. |
labels |
|
Example: This property is equivalent to the labels table resource property. |
default_rounding_mode |
|
Example: This specifies the default rounding mode
that's used for values written to any new
This property is equivalent to the
|
enable_change_history |
|
In preview. Example: Set this property to |
max_staleness |
|
Example: The maximum interval behind the current time where it's
acceptable to read stale data. For example, with
change data capture,
when this option is set, the table copy operation is denied if data is
more stale than the
|
enable_fine_grained_mutations |
|
In preview. Example: Set this property to |
storage_uri |
|
In preview. Example: A fully qualified location prefix for the external folder where data is
stored. Supports Required for managed tables. |
file_format |
|
In preview. Example: The open-source file format in which the table data is stored.
Only Required for managed tables. The default is |
table_format |
|
In preview. Example: The open table format in which metadata-only snapshots are stored.
Only Required for managed tables. The default is |
tags |
<ARRAY<STRUCT<STRING, STRING>>> |
An array of IAM tags for the table, expressed as key-value pairs. The key should be the namespaced key name, and the value should be the short name. |
VALUE is a constant expression containing only literals, query parameters,
and scalar functions.
The constant expression cannot contain:
- A reference to a table
- Subqueries or SQL statements such as
SELECT,CREATE, orUPDATE - User-defined functions, aggregate functions, or analytic functions
- The following scalar functions:
ARRAY_TO_STRINGREPLACEREGEXP_REPLACERANDFORMATLPADRPADREPEATSESSION_USERGENERATE_ARRAYGENERATE_DATE_ARRAY
load_option_list
Specifies options for loading data from external files. The format and uris
options are required. Specify the option list in the following format:
NAME=VALUE, ...
| Options | |
|---|---|
allow_jagged_rows |
If Applies to CSV data. |
allow_quoted_newlines |
If Applies to CSV data. |
bigtable_options |
Only required when creating a Bigtable external table. Specifies the schema of the Bigtable external table in JSON format. For a list of Bigtable table definition options, see
|
column_name_character_map |
Defines the scope of supported column name characters and the
handling behavior of unsupported characters. The default setting is
Supported values include:
Applies to CSV and Parquet data. |
compression |
The compression type of the data source. Supported values include:
Applies to CSV and JSON data. |
decimal_target_types |
Determines how to convert a Example: |
enable_list_inference |
If Applies to Parquet data. |
enable_logical_types |
If Applies to Avro data. |
encoding |
The character encoding of the data. Supported values include:
Applies to CSV data. |
enum_as_string |
If Applies to Parquet data. |
field_delimiter |
The separator for fields in a CSV file. Applies to CSV data. |
format |
The format of the external data.
Supported values for
Supported values for
The value |
hive_partition_uri_prefix |
A common prefix for all source URIs before the partition key encoding begins. Applies only to hive-partitioned external tables. Applies to Avro, CSV, JSON, Parquet, and ORC data. Example: |
file_set_spec_type |
Specifies how to interpret source URIs for load jobs and external tables. Supported values include:
For example, if you have a source URI of |
ignore_unknown_values |
If Applies to CSV and JSON data. |
json_extension |
For JSON data, indicates a particular JSON interchange format. If not specified, BigQuery reads the data as generic JSON records. Supported values include: |
max_bad_records |
The maximum number of bad records to ignore when reading the data. Applies to: CSV, JSON, and Google Sheets data. |
max_staleness |
Applicable for BigLake tables and object tables. Specifies whether cached metadata is used by operations against the table, and how fresh the cached metadata must be in order for the operation to use it. To disable metadata caching, specify 0. This is the default. To enable metadata caching, specify an
interval literal
value between 30 minutes and 7 days. For example, specify
|
null_marker |
The string that represents Applies to CSV data. |
null_markers |
(Preview) The list of strings that represent This option cannot be used with Applies to CSV data. |
object_metadata |
Only required when creating an object table. Set the value of this option to |
preserve_ascii_control_characters |
If Applies to CSV data. |
quote |
The string used to quote data sections in a CSV file. If your data
contains quoted newline characters, also set the
Applies to CSV data. |
skip_leading_rows |
The number of rows at the top of a file to skip when reading the data. Applies to CSV and Google Sheets data. |
source_column_match |
(Preview) This controls the strategy used to match loaded columns to the schema. If this value is unspecified, then the default is based on how the schema is provided. If autodetect is enabled, then the default behavior is to match columns by name. Otherwise, the default is to match columns by position. This is done to keep the behavior backward-compatible. Supported values include:
|
tags |
<ARRAY<STRUCT<STRING, STRING>>>
An array of IAM tags for the table, expressed as key-value pairs. The key should be the namespaced key name, and the value should be the short name. |
time_zone |
(Preview) Default time zone that will apply when parsing timestamp values that have no specific time zone. Check valid time zone names. If this value is not present, the timestamp values without specific time zone is parsed using default time zone UTC. Applies to CSV and JSON data. |
date_format |
(Preview)
Format elements
that define how the DATE values are formatted in the input files (for
example, If this value is present, this format is the only compatible DATE format. Schema autodetection will also decide DATE column type based on this format instead of the existing format. If this value is not present, the DATE field is parsed with the default formats. Applies to CSV and JSON data. |
datetime_format |
(Preview)
Format elements
that define how the DATETIME values are formatted in the input files
(for example, If this value is present, this format is the only compatible DATETIME format. Schema autodetection will also decide DATETIME column type based on this format instead of the existing format. If this value is not present, the DATETIME field is parsed with the default formats. Applies to CSV and JSON data. |
time_format |
(Preview)
Format elements
that define how the TIME values are formatted in the input files (for
example, If this value is present, this format is the only compatible TIME format. Schema autodetection will also decide TIME column type based on this format instead of the existing format. If this value is not present, the TIME field is parsed with the default formats. Applies to CSV and JSON data. |
timestamp_format |
(Preview)
Format elements
that define how the TIMESTAMP values are formatted in the input files
(for example, If this value is present, this format is the only compatible TIMESTAMP format. Schema autodetection will also decide TIMESTAMP column type based on this format instead of the existing format. If this value is not present, the TIMESTAMP field is parsed with the default formats. Applies to CSV and JSON data. |
uris |
For external tables, including object tables, that aren't Bigtable tables:
An array of fully qualified URIs for the external data locations.
Each URI can contain one
asterisk ( The following examples show valid
For Bigtable tables:
The URI identifying the Bigtable table to use as a data source. You can only specify one Bigtable URI. Example:
For more information on constructing a Bigtable URI, see Retrieve the Bigtable URI. |
Examples
The following examples show common use cases for the LOAD DATA statement.
Load data into a table
The following example loads an Avro file into a table. Avro is a self-describing format, so BigQuery infers the schema.
LOAD DATA INTO mydataset.table1 FROM FILES( format='AVRO', uris = ['gs://bucket/path/file.avro'] )
The following example loads two CSV files into a table, using schema autodetection.
LOAD DATA INTO mydataset.table1 FROM FILES( format='CSV', uris = ['gs://bucket/path/file1.csv', 'gs://bucket/path/file2.csv'] )
Load data using a schema
The following example loads a CSV file into a table, using a specified table schema.
LOAD DATA INTO mydataset.table1(x INT64, y STRING) FROM FILES( skip_leading_rows=1, format='CSV', uris = ['gs://bucket/path/file.csv'] )
Set options when creating a new table
The following example creates a new table with a description and an expiration time.
LOAD DATA INTO mydataset.table1 OPTIONS( description="my table", expiration_timestamp="2025-01-01 00:00:00 UTC" ) FROM FILES( format='AVRO', uris = ['gs://bucket/path/file.avro'] )
Overwrite an existing table
The following example overwrites an existing table.
LOAD DATA OVERWRITE mydataset.table1 FROM FILES( format='AVRO', uris = ['gs://bucket/path/file.avro'] )
Load data into a temporary table
The following example loads an Avro file into a temporary table.
LOAD DATA INTO TEMP TABLE mydataset.table1 FROM FILES( format='AVRO', uris = ['gs://bucket/path/file.avro'] )
Specify table partitioning and clustering
The following example creates a table that is partitioned by the
transaction_date field and clustered by the customer_id field. It also
configures the partitions to expire after three days.
LOAD DATA INTO mydataset.table1 PARTITION BY transaction_date CLUSTER BY customer_id OPTIONS( partition_expiration_days=3 ) FROM FILES( format='AVRO', uris = ['gs://bucket/path/file.avro'] )
Load data into a partition
The following example loads data into a selected partition of an ingestion-time partitioned table:
LOAD DATA INTO mydataset.table1 PARTITIONS(_PARTITIONTIME = TIMESTAMP '2016-01-01') PARTITION BY _PARTITIONTIME FROM FILES( format = 'AVRO', uris = ['gs://bucket/path/file.avro'] )
Load a file that is externally partitioned
The following example loads a set of external files that use a hive partitioning layout.
LOAD DATA INTO mydataset.table1 FROM FILES( format='AVRO', uris = ['gs://bucket/path/*'], hive_partition_uri_prefix='gs://bucket/path' ) WITH PARTITION COLUMNS( field_1 STRING, -- column order must match the external path field_2 INT64 )
The following example infers the partitioning layout:
LOAD DATA INTO mydataset.table1 FROM FILES( format='AVRO', uris = ['gs://bucket/path/*'], hive_partition_uri_prefix='gs://bucket/path' ) WITH PARTITION COLUMNS
If you include both column_list and WITH PARTITION COLUMNS, then you must
explicitly list the partitioning columns. For example, the following query
returns an error:
-- This query returns an error. LOAD DATA INTO mydataset.table1 ( x INT64, -- column_list is given but the partition column list is missing y STRING ) FROM FILES( format='AVRO', uris = ['gs://bucket/path/*'], hive_partition_uri_prefix='gs://bucket/path' ) WITH PARTITION COLUMNS
Load data with cross-cloud transfer
Example 1
The following example loads a parquet file named sample.parquet from an Amazon S3
bucket into the test_parquet table with an auto-detect schema:
LOAD DATA INTO mydataset.testparquet FROM FILES ( uris = ['s3://test-bucket/sample.parquet'], format = 'PARQUET' ) WITH CONNECTION `aws-us-east-1.test-connection`
Example 2
The following example loads a CSV file with the prefix sampled* from your
Blob Storage into the test_csv table with predefined column
partitioning by time:
LOAD DATA INTO mydataset.test_csv (Number INT64, Name STRING, Time DATE) PARTITION BY Time FROM FILES ( format = 'CSV', uris = ['azure://test.blob.core.windows.net/container/sampled*'], skip_leading_rows=1 ) WITH CONNECTION `azure-eastus2.test-connection`
Example 3
The following example overwrites the existing table test_parquet with
data from a file named sample.parquet with an auto-detect schema:
LOAD DATA OVERWRITE mydataset.testparquet FROM FILES ( uris = ['s3://test-bucket/sample.parquet'], format = 'PARQUET' ) WITH CONNECTION `aws-us-east-1.test-connection`