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Update

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This article is generated by AI translation.

Use LambdaTemplate to update data in three ways, and mix them as needed:

Tip

For building conditions during updates, see where builder.

Update fields​

Basic usage 1: Lambda
LambdaTemplate lambda = ...;
int result = lambda.update(User.class)
                   .eq(User::getId, 1)              // match condition
                   .updateTo(User::getName, "Mary") // update field via Lambda
                   .updateTo(User::getStatus, 2)    // chain multiple field updates
                   .doUpdate();
// result is the affected row count
Basic usage 2: String property
LambdaTemplate lambda = ...;
int result = lambda.update(User.class)
                   .eq(User::getId, 1)               // match condition
                   .updateToUsingStr("name", "Mary") // update field via property name
                   .updateToUsingStr("status", 2)    // chain multiple field updates
                   .doUpdate();
// result is the affected row count

Sample-driven​

When many fields need updating, build a sample object to avoid long updateTo chains.

Use a Bean as the sample
User sample = new User();
sample.setName("new name");
sample.setStatus(2);

LambdaTemplate lambda = ...;
int result = lambda.update(User.class)
                   .ne(User::getStatus, 2) // match records whose status != 2
                   .updateToSample(sample) // update name and status
                   .doUpdate();
// result is the affected row count
Use a Map as the sample
Map<String, Object> sample = new HashMap<>();
sample.put("name", "new name");
sample.put("status", 2);

LambdaTemplate lambda = ...;
int result = lambda.update(User.class)
                   .ne(User::getStatus, 2)    // match records whose status != 2
                   .updateToSampleMap(sample) // update name and status
                   .doUpdate();
// result is the affected row count
Usage notes
  • updateToSample only looks at non-null sample properties:
    • Set fields you do not want to update to null in the sample.
    • Avoid primitive properties (byte, short, int, long, float, double, char) in samples.
    • To update a field to null, add field updates.
  • If updateToSample is called multiple times, later samples override overlapping fields.

Replace row​

replace the entire row with the provided data.

Use a Bean
User user = new User();
user.setName("new name");
user.setStatus(2);

LambdaTemplate lambda = ...;
int result = lambda.update(User.class)
                   .ne(User::getStatus, 2) // match records whose status != 2
                   .updateRow(user)        // all columns use values from user
                   .doUpdate();
// result is the affected row count

In the example above:

  • User has four properties: id, name, status, age.
  • Two properties are set on the update object.
  • id is the primary key.

The final update sets name, status, and age; age becomes null.

Update primary key​

Important

Primary key columns are excluded by default. Therefore:

  • updateToSample and updateRow ignore primary keys unless allowed.
  • Updating a primary key elsewhere throws an exception.

Call allowUpdateKey to permit updating primary keys.

LambdaTemplate lambda = ...;
int result = lambda.update(User.class)
                   .eq(User::getId, 1)       // match condition
                   .allowUpdateKey()         // allow updating primary key
                   .updateTo(User::getId, 2) // update primary key
                   .doUpdate();
// result is the affected row count

Empty conditions​

Updates without any conditions are dangerous and blocked by default.

To update the entire table, call allowEmptyWhere for this operation.

LambdaTemplate lambda = ...;
int result = lambda.update(User.class)
                   .allowEmptyWhere()            // allow no conditions
                   .updateTo(User::getStatus, 2) // set status to 2 for the whole table
                   .doUpdate();
// result is the affected row count