Object DbConnection
The database connection object is used to establish and maintain a database connection session.
Inheritance
Member attributes
type
String, query the current connection database type
1readonly String DbConnection.type;
Member function
close
Close the current database connection
1DbConnection.close() async;
use
Select the default database for the current database connection
1DbConnection.use(String dbName) async;
Call parameters:
- dbName: String, specify the database name
begin
Start a transaction on the current database connection
1DbConnection.begin(String point = "") async;
Call parameters:
- point: String, specify the name of the transaction, not specified by default
commit
Commit the transaction on the current database connection
1DbConnection.commit(String point = "") async;
Call parameters:
- point: String, specify the name of the transaction, not specified by default
rollback
Roll back the transaction on the current database connection
1DbConnection.rollback(String point = "") async;
Call parameters:
- point: String, specify the name of the transaction, not specified by default
trans
Enter a transaction to execute a function, and submit or roll back according to the execution of the function
1Boolean DbConnection.trans(Function func);
Call parameters:
- func: Function, a function executed in a transactional manner
Return result:
- Boolean, Returns whether the transaction is committed, true for normal commit, false for rollback, and an error is thrown if there is an error in the transaction
The execution of func has three results:
- The function returns normally, including the end of the operation and the active return, at which time the transaction will be automatically committed
- The function returns false, at this time the transaction will be rolled back
- The function runs incorrectly, the transaction is automatically rolled back
Enter a transaction to execute a function, and submit or roll back according to the execution of the function
1
2Boolean DbConnection.trans(String point,
Function func);
Call parameters:
- point: String, specify the name of the transaction
- func: Function, a function executed in a transactional manner
Return result:
- Boolean, Returns whether the transaction is committed, true for normal commit, false for rollback, and an error is thrown if there is an error in the transaction
The execution of func has three results:
- The function returns normally, including the end of the operation and the active return, at which time the transaction will be automatically committed
- The function returns false, at this time the transaction will be rolled back
- The function runs incorrectly, the transaction is automatically rolled back
execute
Execute a sql command and return the execution result
1NArray DbConnection.execute(String sql) async;
Call parameters:
- sql: String, string
Return result:
- NArray, Returns an array containing the result records. If the request is UPDATE or INSERT, the returned result will also contain affected and insertId. mssql does not support insertId.
Execute an sql command, and return the execution result, can format the string according to the parameters
1
2NArray DbConnection.execute(String sql,
...args) async;
Call parameters:
- sql: String, format string, optional parameters are specified with ?. For example:'SELECT FROM TEST WHERE [id]=?'
- args: ..., optional parameter list
Return result:
- NArray, Returns an array containing the result records. If the request is UPDATE or INSERT, the returned result will also contain affected and insertId. mssql does not support insertId.
createTable
Create data table
1DbConnection.createTable(Object opts) async;
Call parameters:
- opts: Object, parameter list
dropTable
Delete data table
1DbConnection.dropTable(Object opts) async;
Call parameters:
- opts: Object, parameter list
createIndex
Create data table index
1DbConnection.createIndex(Object opts) async;
Call parameters:
- opts: Object, parameter list
dropIndex
Delete data table index
1DbConnection.dropIndex(Object opts) async;
Call parameters:
- opts: Object, parameter list
insert
Insert new record
1Number DbConnection.insert(Object opts) async;
Call parameters:
- opts: Object, parameter list
Return result:
- Number, Returns the id containing the insert, or 0 if the engine does not support it
find
Query data according to specified conditions
1NArray DbConnection.find(Object opts) async;
Call parameters:
- opts: Object, parameter list
Return result:
- NArray, Returns the record containing the result
count
Count the number of data records according to the specified conditions
1Integer DbConnection.count(Object opts) async;
Call parameters:
- opts: Object, parameter list
Return result:
- Integer, Returns the number of records containing the result
update
Update data according to specified conditions
1Integer DbConnection.update(Object opts) async;
Call parameters:
- opts: Object, parameter list
Return result:
- Integer, Returns the number of records containing updates
remove
Delete data according to specified conditions
1Integer DbConnection.remove(Object opts) async;
Call parameters:
- opts: Object, optional parameter list
Return result:
- Integer, Returns the number of records containing updates
format
Format a sql command and return the formatted result
1
2String DbConnection.format(String method,
Object opts);
Call parameters:
- method: String, specify the requested method
- opts: Object, optional parameter list
Return result:
- String, Returns the formatted sql command
Format a sql command and return the formatted result
1
2String DbConnection.format(String sql,
...args);
Call parameters:
- sql: String, format string, optional parameters are specified with ?. For example:'SELECT FROM TEST WHERE [id]=?'
- args: ..., optional parameter list
Return result:
- String, Returns the formatted sql command
toString
Returns the string representation of the object, generally returns "[Native Object]", the object can be re-implemented according to its own characteristics
1String DbConnection.toString();
Return result:
- String, Returns the string representation of the object
toJSON
Returns the JSON format representation of the object, generally returns a collection of readable attributes defined by the object
1Value DbConnection.toJSON(String key = "");
Call parameters:
- key: String, unused
Return result:
- Value, Returns a value containing JSON serializable