下面列出了android.database.DatabaseUtils#getSqlStatementType ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
/**
* Performs special reinterpretation of certain SQL statements such as "BEGIN",
* "COMMIT" and "ROLLBACK" to ensure that transaction state invariants are
* maintained.
*
* This function is mainly used to support legacy apps that perform their
* own transactions by executing raw SQL rather than calling {@link #beginTransaction}
* and the like.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param connectionFlags The connection flags to use if a connection must be
* acquired by this operation. Refer to {@link SQLiteConnectionPool}.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* @return True if the statement was of a special form that was handled here,
* false otherwise.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
private boolean executeSpecial(String sql, Object[] bindArgs, int connectionFlags,
CancellationSignal cancellationSignal) {
if (cancellationSignal != null) {
cancellationSignal.throwIfCanceled();
}
final int type = DatabaseUtils.getSqlStatementType(sql);
switch (type) {
case DatabaseUtils.STATEMENT_BEGIN:
beginTransaction(TRANSACTION_MODE_EXCLUSIVE, null, connectionFlags,
cancellationSignal);
return true;
case DatabaseUtils.STATEMENT_COMMIT:
setTransactionSuccessful();
endTransaction(cancellationSignal);
return true;
case DatabaseUtils.STATEMENT_ABORT:
endTransaction(cancellationSignal);
return true;
}
return false;
}
private int executeSql(String sql, Object[] bindArgs) throws SQLException {
acquireReference();
try {
if (DatabaseUtils.getSqlStatementType(sql) == DatabaseUtils.STATEMENT_ATTACH) {
boolean disableWal = false;
synchronized (mLock) {
if (!mHasAttachedDbsLocked) {
mHasAttachedDbsLocked = true;
disableWal = true;
}
}
if (disableWal) {
disableWriteAheadLogging();
}
}
SQLiteStatement statement = new SQLiteStatement(this, sql, bindArgs);
try {
return statement.executeUpdateDelete();
} finally {
statement.close();
}
} finally {
releaseReference();
}
}
/**
* Performs special reinterpretation of certain SQL statements such as "BEGIN",
* "COMMIT" and "ROLLBACK" to ensure that transaction state invariants are
* maintained.
*
* This function is mainly used to support legacy apps that perform their
* own transactions by executing raw SQL rather than calling {@link #beginTransaction}
* and the like.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param connectionFlags The connection flags to use if a connection must be
* acquired by this operation. Refer to {@link SQLiteConnectionPool}.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* @return True if the statement was of a special form that was handled here,
* false otherwise.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
private boolean executeSpecial(String sql, Object[] bindArgs, int connectionFlags,
CancellationSignal cancellationSignal) {
if (cancellationSignal != null) {
cancellationSignal.throwIfCanceled();
}
final int type = DatabaseUtils.getSqlStatementType(sql);
switch (type) {
case DatabaseUtils.STATEMENT_BEGIN:
beginTransaction(TRANSACTION_MODE_EXCLUSIVE, null, connectionFlags,
cancellationSignal);
return true;
case DatabaseUtils.STATEMENT_COMMIT:
setTransactionSuccessful();
endTransaction(cancellationSignal);
return true;
case DatabaseUtils.STATEMENT_ABORT:
endTransaction(cancellationSignal);
return true;
}
return false;
}
/** {@hide} */
public int executeSql(String sql, Object[] bindArgs) throws SQLException {
acquireReference();
try {
final int statementType = DatabaseUtils.getSqlStatementType(sql);
if (statementType == DatabaseUtils.STATEMENT_ATTACH) {
boolean disableWal = false;
synchronized (mLock) {
if (!mHasAttachedDbsLocked) {
mHasAttachedDbsLocked = true;
disableWal = true;
mConnectionPoolLocked.disableIdleConnectionHandler();
}
}
if (disableWal) {
disableWriteAheadLogging();
}
}
try (SQLiteStatement statement = new SQLiteStatement(this, sql, bindArgs)) {
return statement.executeUpdateDelete();
} finally {
// If schema was updated, close non-primary connections, otherwise they might
// have outdated schema information
if (statementType == DatabaseUtils.STATEMENT_DDL) {
mConnectionPoolLocked.closeAvailableNonPrimaryConnectionsAndLogExceptions();
}
}
} finally {
releaseReference();
}
}
private PreparedStatement acquirePreparedStatement(String sql) {
PreparedStatement statement = mPreparedStatementCache.get(sql);
boolean skipCache = false;
if (statement != null) {
if (!statement.mInUse) {
return statement;
}
// The statement is already in the cache but is in use (this statement appears
// to be not only re-entrant but recursive!). So prepare a new copy of the
// statement but do not cache it.
skipCache = true;
}
final long statementPtr = nativePrepareStatement(mConnectionPtr, sql);
try {
final int numParameters = nativeGetParameterCount(mConnectionPtr, statementPtr);
final int type = DatabaseUtils.getSqlStatementType(sql);
final boolean readOnly = nativeIsReadOnly(mConnectionPtr, statementPtr);
statement = obtainPreparedStatement(sql, statementPtr, numParameters, type, readOnly);
if (!skipCache && isCacheable(type)) {
mPreparedStatementCache.put(sql, statement);
statement.mInCache = true;
}
} catch (RuntimeException ex) {
// Finalize the statement if an exception occurred and we did not add
// it to the cache. If it is already in the cache, then leave it there.
if (statement == null || !statement.mInCache) {
nativeFinalizeStatement(mConnectionPtr, statementPtr);
}
throw ex;
}
statement.mInUse = true;
return statement;
}
private PreparedStatement acquirePreparedStatement(String sql) {
PreparedStatement statement = mPreparedStatementCache.get(sql);
boolean skipCache = false;
if (statement != null) {
if (!statement.mInUse) {
return statement;
}
// The statement is already in the cache but is in use (this statement appears
// to be not only re-entrant but recursive!). So prepare a new copy of the
// statement but do not cache it.
skipCache = true;
}
final long statementPtr = nativePrepareStatement(mConnectionPtr, sql);
try {
final int numParameters = nativeGetParameterCount(mConnectionPtr, statementPtr);
final int type = DatabaseUtils.getSqlStatementType(sql);
final boolean readOnly = nativeIsReadOnly(mConnectionPtr, statementPtr);
statement = obtainPreparedStatement(sql, statementPtr, numParameters, type, readOnly);
if (!skipCache && isCacheable(type)) {
mPreparedStatementCache.put(sql, statement);
statement.mInCache = true;
}
} catch (RuntimeException ex) {
// Finalize the statement if an exception occurred and we did not add
// it to the cache. If it is already in the cache, then leave it there.
if (statement == null || !statement.mInCache) {
nativeFinalizeStatement(mConnectionPtr, statementPtr);
}
throw ex;
}
statement.mInUse = true;
return statement;
}
SQLiteProgram(SQLiteDatabase db, String sql, Object[] bindArgs,
CancellationSignal cancellationSignalForPrepare) {
mDatabase = db;
mSql = sql.trim();
int n = DatabaseUtils.getSqlStatementType(mSql);
switch (n) {
case DatabaseUtils.STATEMENT_BEGIN:
case DatabaseUtils.STATEMENT_COMMIT:
case DatabaseUtils.STATEMENT_ABORT:
mReadOnly = false;
mColumnNames = EMPTY_STRING_ARRAY;
mNumParameters = 0;
break;
default:
boolean assumeReadOnly = (n == DatabaseUtils.STATEMENT_SELECT);
SQLiteStatementInfo info = new SQLiteStatementInfo();
db.getThreadSession().prepare(mSql,
db.getThreadDefaultConnectionFlags(assumeReadOnly),
cancellationSignalForPrepare, info);
mReadOnly = info.readOnly;
mColumnNames = info.columnNames;
mNumParameters = info.numParameters;
break;
}
if (bindArgs != null && bindArgs.length > mNumParameters) {
throw new IllegalArgumentException("Too many bind arguments. "
+ bindArgs.length + " arguments were provided but the statement needs "
+ mNumParameters + " arguments.");
}
if (mNumParameters != 0) {
mBindArgs = new Object[mNumParameters];
if (bindArgs != null) {
System.arraycopy(bindArgs, 0, mBindArgs, 0, bindArgs.length);
}
} else {
mBindArgs = null;
}
}
SQLiteProgram(SQLiteDatabase db, String sql, Object[] bindArgs,
CancellationSignal cancellationSignalForPrepare) {
mDatabase = db;
mSql = sql.trim();
int n = DatabaseUtils.getSqlStatementType(mSql);
switch (n) {
case DatabaseUtils.STATEMENT_BEGIN:
case DatabaseUtils.STATEMENT_COMMIT:
case DatabaseUtils.STATEMENT_ABORT:
mReadOnly = false;
mColumnNames = EMPTY_STRING_ARRAY;
mNumParameters = 0;
break;
default:
boolean assumeReadOnly = (n == DatabaseUtils.STATEMENT_SELECT);
SQLiteStatementInfo info = new SQLiteStatementInfo();
db.getThreadSession().prepare(mSql,
db.getThreadDefaultConnectionFlags(assumeReadOnly),
cancellationSignalForPrepare, info);
mReadOnly = info.readOnly;
mColumnNames = info.columnNames;
mNumParameters = info.numParameters;
break;
}
if (bindArgs != null && bindArgs.length > mNumParameters) {
throw new IllegalArgumentException("Too many bind arguments. "
+ bindArgs.length + " arguments were provided but the statement needs "
+ mNumParameters + " arguments.");
}
if (mNumParameters != 0) {
mBindArgs = new Object[mNumParameters];
if (bindArgs != null) {
System.arraycopy(bindArgs, 0, mBindArgs, 0, bindArgs.length);
}
} else {
mBindArgs = null;
}
}