loadData

Loads data from a CSV file into an existing table when you add it to your changelog.

Uses

After you create a table in your database using the Liquibase createTable Change Type, you can populate it with data from an external CSV (comma-separated value) file using loadData. This may be useful when you're setting up a new application or migrating data from another system.

Syntax rules

A value of NULL (regardless of capitalization) in a cell will be converted to a database NULL rather than the string NULL.

Lines starting with a number sign (#) are treated as comments. You can change the comment pattern by specifying commentLineStartsWith attribute. To disable comments, set commentLineStartsWith to an empty value.

If the data type for a load column is set to NUMERIC, numbers are parsed in the US locale (for example: 123.45). Date/Time values included in the CSV file should be in ISO format to be parsed correctly by Liquibase. Liquibase initially sets the date format to yyyy-MM-dd'T'HH:mm:ss and then it checks for two special cases which will override the data format string:

  • If the string representing the date/time includes a period (.), then the date format is changed to yyyy-MM-dd'T'HH:mm:ss.SSS.
  • If the string representing the date/time includes a space, then the date format is changed to yyyy-MM-dd HH:mm:ss.

Once the date format string is set, Liquibase will then call the SimpleDateFormat.parse() method attempting to parse the input string so that it can return a date/time. If problems occur, then a ParseException is thrown and the input string is treated as a String for the INSERT command to be generated. If UUID type is used, UUID value is stored as string and NULL in cell is supported.

Non-ISO date format

To use a non-ISO format for your dates:

  1. Ensure you are using Liquibase 4.4.0 or later.
  2. Add an ALTER SESSION command in SQL to your changeset.
  3. Specify the DATE type in the affected columns of your loadData changeset.

For example, in an Oracle database using MM/DD/YYYY HH:MI:SS AM:

<changeSet author="Liquibase" id="0">
    <sql>
        ALTER SESSION SET NLS_DATE_FORMAT = 'MM/DD/YYYY HH:MI:SS AM';
    </sql>
    <loadData>
        <column name="EXPIRATION_DATE" type="DATE 'MM/DD/YYYY HH:MI:SS AM'"/>
    </loadData>
<changeSet>

Load data with the loadData tag

Including specific columns

All CSV columns are used by default while generating SQL even if they are not described in the columns property. If you want to skip specific headers in the CSV file, set the value of the type property to skip.

Imagine that you have a table with columns col_1,col_2,col_3. To load only columns col_1 and col_2, specify col_3 in the column tag and set its type to skip:

<column name="col_3" header="col_3" type="skip" />

Creating a loadable CSV

You can load data from an existing CSV file (names.csv):

id,first,last
0,john,doe
1,eric,smith
2,cat,jones

In your changelog, create a table called populated. Then create a loadData changeset to insert data from the CSV into that table. For example:

<changeSet author="your.name" id="1::emptyTable">
    <createTable tableName="populated">
        <column name="id" type="int" autoIncrement="true">
            <constraints primaryKey="true" nullable="false"/>
        </column>
        <column name="first" type="varchar(50)"/>
        <column name="last" type="varchar(50)"/>
    </createTable>
</changeSet>

<changeSet author="your.name" id="2::dataForTable" labels="data">
    <loadData file="names.csv" tableName="populated"/>
</changeSet>

In your command line, deploy your change:

liquibase update

Note: Liquibase 4.4.0+ assumes that spaces in the CSV header are part of the column names and does not strip them. If your header contains spaces and the column names in your changeset don't, Liquibase throws an error. To resolve this, use the --trim-load-data-file-header parameter in Liquibase 4.29.0.

Generating loadData changesets and a CSV from your current database

You can also capture the current state of your database as a CSV with the generate-changelog command and dataOutputDirectory attribute. This generates the loadData changesets with the columns from the CSV, and formats your data as a CSV in the folder you specified for dataOutputDirectory:

liquibase generate-changelog --diffTypes=tables,columns,data --dataOutputDirectory=myData --changelog-file=output_changelog.xml

If you don't use the --dataOutputDirectory flag while running the command, Liquibase uses insert statements in your generated changelog instead of columns in the loadData tag, and also formats your data as a CSV in the folder you specified for dataOutputDirectory:

liquibase --diffTypes=tables,columns,data --changelog-file=myChangelog.xml generate-changelog

Available attributes

Name Description Required for Supports Since
catalogName

Name of the catalog

all 3.0
commentLineStartsWith

Lines starting with this are treated as comment and ignored.

  all  
encoding Encoding of the CSV file (defaults to UTF-8) all
file CSV file to load all all
quotchar The quote character for string fields containing the separator character. all
relativeToChangelogFile

Specifies whether the file path is relative to the changelog file rather than looked up in the search path. Default: false.

all
schemaName

Name of the schema

all
separator Character separating the fields. all
tableName

Name of the table to insert or update data in

all all
usePreparedStatements Use prepared statements instead of insert statement strings if the database supports it.   all  

Nested tags

Name Description Required for Supports Multiple allowed
column

Column mapping and defaults can be defined. The header or index attributes need to be defined. If the header name in the CSV is different than the column, name needs to be inserted. If no column is defined at all, the type is taken from a database. Otherwise, for non-string columns the type definition might be required.

Note: YAML and JSON changelogs using the column tag must nest it within a columns tag.

all yes

Nested property attributes

Name Description
name Name of the column (Required).
type Data type of the column. Its value has to be one of the accepted values of LOAD_DATA_TYPE. If you want to skip loading a specific column, use the skip data type described earlier. Otherwise, all columns in the CSV file will be used.
header Name of the column in the CSV file from which the value for the column will be taken if it's different from the column name. Ignored if index is also defined.
index Index of the column in the CSV file from which the value for the column will be taken.

Examples

databaseChangeLog:
-  changeSet:
     id: loadData-example
     author: liquibase-docs
     changes:
     -  loadData:
         catalogName:  cat
         columns:
         -  column:
             header:  header1
             name:  id
             type:  NUMERIC
         -  column:
             index:  3
             name:  name
             type:  BOOLEAN
         commentLineStartsWith:  //
         encoding:  UTF-8
         file:  example/users.csv
         quotchar:  ''''
         relativeToChangelogFile:  true
         schemaName:  public
         separator:  ;
         tableName:  person
         usePreparedStatements:  true
{
    "databaseChangeLog": [
        {
            "changeSet": {
                "id": "loadData-example",
                "author": "liquibase-docs",
                "changes": [
                    {
                        "loadData": {
                            "catalogName": "cat",
                            "columns": [
                                {
                                    "column": {
                                        "header": "header1",
                                        "name": "id",
                                        "type": "NUMERIC"
                                    }
                                },
                                {
                                    "column": {
                                        "index": 3,
                                        "name": "name",
                                        "type": "BOOLEAN"
                                    }
                                }
                            ],
                            "commentLineStartsWith": "//",
                            "encoding": "UTF-8",
                            "file": "example/users.csv",
                            "quotchar": "'",
                            "relativeToChangelogFile": true,
                            "schemaName": "public",
                            "separator": ";",
                            "tableName": "person",
                            "usePreparedStatements": true
                        }
                    }
                ]
            }
        }
    ]
}
<databaseChangeLog
    xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
    xmlns:pro="http://www.liquibase.org/xml/ns/pro"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd
        http://www.liquibase.org/xml/ns/dbchangelog-ext
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
        http://www.liquibase.org/xml/ns/pro
        http://www.liquibase.org/xml/ns/pro/liquibase-pro-latest.xsd">

    <changeSet author="liquibase-docs" id="loadData-example">
        <loadData catalogName="cat"
              commentLineStartsWith="//"
              encoding="UTF-8"
              file="example/users.csv"
              quotchar="'"
              relativeToChangelogFile="true"
              schemaName="public"
              separator=";"
              tableName="person"
              usePreparedStatements="true">
            <column header="header1"
                 name="id"
                 type="NUMERIC"/>
            <column index="3"  
                 name="name"
                 type="BOOLEAN"/>
        </loadData>
    </changeSet>

</databaseChangeLog>

Database support

Database Notes Auto Rollback
DB2/LUW Supported No
DB2/z Supported No
Derby Supported No
Firebird Supported No
Google BigQuery Supported No
H2 Supported No
HyperSQL Supported No
INGRES Supported No
Informix Supported No
MariaDB Supported No
MySQL Supported No
Oracle Supported No
PostgreSQL Supported No
Snowflake Supported No
SQL Server Supported No
SQLite Supported No
Sybase Supported No
Sybase Anywhere Supported No