/// <summary>
/// Compare two schema changes, used for unit tests to compare expected and actual schema change objects
/// </summary>
/// <param name="toCompare">The schema change to compare to</param>
/// <returns>True if all properties are the same, false otherwise</returns>
public bool Equals(SchemaChange toCompare)
{
return(DdeID == toCompare.DdeID &&
EventType == toCompare.EventType &&
SchemaName == toCompare.SchemaName &&
TableName == toCompare.TableName &&
ColumnName == toCompare.ColumnName &&
NewColumnName == toCompare.NewColumnName &&
DataType.Equals(DataType, toCompare.DataType));
}
public void TestEquals()
{
SchemaChange one = new SchemaChange(1, SchemaChangeType.Add, "sname", "tname", "cname", "ncname");
SchemaChange two = new SchemaChange(1, SchemaChangeType.Add, "sname", "tname", "cname", "ncname");
Assert.True(one.Equals(two));
two = new SchemaChange(1, SchemaChangeType.Drop, "sname", "tname", "cname", "ncname");
Assert.False(one.Equals(two));
two = new SchemaChange(1, SchemaChangeType.Add, "asdf", "tname", "cname", "ncname");
Assert.False(one.Equals(two));
two = new SchemaChange(1, SchemaChangeType.Add, "sname", "tname", "asdf", "ncname");
Assert.False(one.Equals(two));
}
/// <summary>
/// Parse XML EVENTDATA and create zero or more SchemaChange objects from that
/// </summary>
/// <param name="tables">Array of table configuration objects</param>
/// <param name="dbName">Database for retrieving data type info</param>
public List<SchemaChange> Parse(IEnumerable<TableConf> tables, IDataUtils dataUtils, string dbName)
{
var schemaChanges = new List<SchemaChange>();
string columnName;
string tableName;
SchemaChangeType changeType;
DataType dataType;
SchemaChange sc;
string newColumnName;
XmlNode node;
var xml = new XmlDocument();
xml.LoadXml(EventData);
if (xml == null) {
Console.WriteLine("XML failed to load");
Console.WriteLine(EventData);
}
string eventType = xml.SelectSingleNode("EVENT_INSTANCE/EventType").InnerText;
if (eventType == "ALTER_TABLE") {
node = xml.SelectSingleNode("EVENT_INSTANCE/AlterTableActionList");
} else if (eventType == "RENAME") {
node = xml.SelectSingleNode("EVENT_INSTANCE/Parameters");
} else {
//this is a DDL event type that we don't care about publishing, so ignore it
return schemaChanges;
}
if (node == null) {
//we'll get here on events that do an ALTER_TABLE but don't change any columns,
//such as "alter table enable change_tracking"
return schemaChanges;
}
if (node.FirstChild.Name == "Param") {
tableName = xml.SelectSingleNode("/EVENT_INSTANCE/TargetObjectName").InnerText;
} else {
tableName = xml.SelectSingleNode("/EVENT_INSTANCE/ObjectName").InnerText;
}
string schemaName = xml.SelectSingleNode("/EVENT_INSTANCE/SchemaName").InnerText;
//String.Compare method returns 0 if the strings are equal, the third "true" flag is for a case insensitive comparison
//Get table config object
TableConf t = tables.SingleOrDefault(item => String.Compare(item.Name, tableName, ignoreCase: true) == 0);
if (t == null) {
//the DDL event applies to a table not in our so we just ignore it
return schemaChanges;
}
switch (node.FirstChild.Name) {
case "Param":
changeType = SchemaChangeType.Rename;
columnName = xml.SelectSingleNode("/EVENT_INSTANCE/ObjectName").InnerText;
newColumnName = xml.SelectSingleNode("/EVENT_INSTANCE/NewObjectName").InnerText;
if (t.ColumnList == null || t.ColumnList.Contains(columnName, StringComparer.OrdinalIgnoreCase)) {
sc = new SchemaChange(DdeID, changeType, schemaName, tableName, columnName, newColumnName);
schemaChanges.Add(sc);
}
break;
case "Alter":
changeType = SchemaChangeType.Modify;
foreach (XmlNode xColumn in xml.SelectNodes("/EVENT_INSTANCE/AlterTableActionList/Alter/Columns/Name")) {
columnName = xColumn.InnerText;
if (t.ColumnList == null || t.ColumnList.Contains(columnName, StringComparer.OrdinalIgnoreCase)) {
try {
dataType = ParseDataType(dataUtils.GetDataType(dbName, tableName, schemaName, columnName));
sc = new SchemaChange(DdeID, changeType, schemaName, tableName, columnName, null, dataType);
schemaChanges.Add(sc);
} catch (DoesNotExistException) {
//if we get a does not exist exception, it generally means the column was created and then dropped,
//which is ok.
break;
}
}
}
break;
case "Create":
changeType = SchemaChangeType.Add;
tableName = xml.SelectSingleNode("/EVENT_INSTANCE/ObjectName").InnerText;
foreach (XmlNode xColumn in xml.SelectNodes("/EVENT_INSTANCE/AlterTableActionList/Create/Columns/Name")) {
columnName = xColumn.InnerText;
//if column list is specified, only publish schema changes if the column is already in the list. we don't want
//slaves adding a new column that we don't plan to publish changes for.
//if column list is null, we want changes associated with all columns.
if (t.ColumnList == null || t.ColumnList.Contains(columnName, StringComparer.OrdinalIgnoreCase)) {
try {
var type = dataUtils.GetDataType(dbName, tableName, schemaName, columnName);
dataType = ParseDataType(type);
sc = new SchemaChange(DdeID, changeType, schemaName, tableName, columnName, null, dataType);
schemaChanges.Add(sc);
} catch (DoesNotExistException) {
//if we get a does not exist exception, it generally means the column was created and then dropped,
//which is ok.
break;
}
}
}
break;
case "Drop":
changeType = SchemaChangeType.Drop;
tableName = xml.SelectSingleNode("/EVENT_INSTANCE/ObjectName").InnerText;
foreach (XmlNode xColumn in xml.SelectNodes("/EVENT_INSTANCE/AlterTableActionList/Drop/Columns/Name")) {
columnName = xColumn.InnerText;
if (t.ColumnList == null || t.ColumnList.Contains(columnName, StringComparer.OrdinalIgnoreCase)) {
sc = new SchemaChange(DdeID, changeType, schemaName, tableName, columnName, null, null);
schemaChanges.Add(sc);
}
}
break;
}
return schemaChanges;
}
/// <summary>
/// Compare two schema changes, used for unit tests to compare expected and actual schema change objects
/// </summary>
/// <param name="toCompare">The schema change to compare to</param>
/// <returns>True if all properties are the same, false otherwise</returns>
public bool Equals(SchemaChange toCompare)
{
return (DdeID == toCompare.DdeID
&& EventType == toCompare.EventType
&& SchemaName == toCompare.SchemaName
&& TableName == toCompare.TableName
&& ColumnName == toCompare.ColumnName
&& NewColumnName == toCompare.NewColumnName
&& DataType.Equals(DataType, toCompare.DataType));
}
/// <summary>
/// Parse XML EVENTDATA and create zero or more SchemaChange objects from that
/// </summary>
/// <param name="tables">Array of table configuration objects</param>
/// <param name="dbName">Database for retrieving data type info</param>
public List <SchemaChange> Parse(IEnumerable <TableConf> tables, IDataUtils dataUtils, string dbName)
{
var schemaChanges = new List <SchemaChange>();
string columnName;
string tableName;
SchemaChangeType changeType;
DataType dataType;
SchemaChange sc;
string newColumnName;
XmlNode node;
var xml = new XmlDocument();
xml.LoadXml(EventData);
if (xml == null)
{
Console.WriteLine("XML failed to load");
Console.WriteLine(EventData);
}
string eventType = xml.SelectSingleNode("EVENT_INSTANCE/EventType").InnerText;
if (eventType == "ALTER_TABLE")
{
node = xml.SelectSingleNode("EVENT_INSTANCE/AlterTableActionList");
}
else if (eventType == "RENAME")
{
node = xml.SelectSingleNode("EVENT_INSTANCE/Parameters");
}
else
{
//this is a DDL event type that we don't care about publishing, so ignore it
return(schemaChanges);
}
if (node == null)
{
//we'll get here on events that do an ALTER_TABLE but don't change any columns,
//such as "alter table enable change_tracking"
return(schemaChanges);
}
if (node.FirstChild.Name == "Param")
{
tableName = xml.SelectSingleNode("/EVENT_INSTANCE/TargetObjectName").InnerText;
}
else
{
tableName = xml.SelectSingleNode("/EVENT_INSTANCE/ObjectName").InnerText;
}
string schemaName = xml.SelectSingleNode("/EVENT_INSTANCE/SchemaName").InnerText;
//String.Compare method returns 0 if the strings are equal, the third "true" flag is for a case insensitive comparison
//Get table config object
TableConf t = tables.SingleOrDefault(item => String.Compare(item.Name, tableName, ignoreCase: true) == 0);
if (t == null)
{
//the DDL event applies to a table not in our so we just ignore it
return(schemaChanges);
}
switch (node.FirstChild.Name)
{
case "Param":
changeType = SchemaChangeType.Rename;
columnName = xml.SelectSingleNode("/EVENT_INSTANCE/ObjectName").InnerText;
newColumnName = xml.SelectSingleNode("/EVENT_INSTANCE/NewObjectName").InnerText;
if (t.ColumnList == null || t.ColumnList.Contains(columnName, StringComparer.OrdinalIgnoreCase))
{
sc = new SchemaChange(DdeID, changeType, schemaName, tableName, columnName, newColumnName);
schemaChanges.Add(sc);
}
break;
case "Alter":
changeType = SchemaChangeType.Modify;
foreach (XmlNode xColumn in xml.SelectNodes("/EVENT_INSTANCE/AlterTableActionList/Alter/Columns/Name"))
{
columnName = xColumn.InnerText;
if (t.ColumnList == null || t.ColumnList.Contains(columnName, StringComparer.OrdinalIgnoreCase))
{
try {
dataType = DataType.ParseDataType(dataUtils.GetDataType(dbName, tableName, schemaName, columnName));
sc = new SchemaChange(DdeID, changeType, schemaName, tableName, columnName, null, dataType);
schemaChanges.Add(sc);
} catch (DoesNotExistException) {
//if we get a does not exist exception, it generally means the column was created and then dropped,
//which is ok.
break;
}
}
}
break;
case "Create":
changeType = SchemaChangeType.Add;
tableName = xml.SelectSingleNode("/EVENT_INSTANCE/ObjectName").InnerText;
foreach (XmlNode xColumn in xml.SelectNodes("/EVENT_INSTANCE/AlterTableActionList/Create/Columns/Name"))
{
columnName = xColumn.InnerText;
//if column list is specified, only publish schema changes if the column is already in the list. we don't want
//slaves adding a new column that we don't plan to publish changes for.
//if column list is null, we want changes associated with all columns.
if (t.ColumnList == null || t.ColumnList.Contains(columnName, StringComparer.OrdinalIgnoreCase))
{
try {
var type = dataUtils.GetDataType(dbName, tableName, schemaName, columnName);
dataType = DataType.ParseDataType(type);
sc = new SchemaChange(DdeID, changeType, schemaName, tableName, columnName, null, dataType);
schemaChanges.Add(sc);
} catch (DoesNotExistException) {
//if we get a does not exist exception, it generally means the column was created and then dropped,
//which is ok.
break;
}
}
}
break;
case "Drop":
changeType = SchemaChangeType.Drop;
tableName = xml.SelectSingleNode("/EVENT_INSTANCE/ObjectName").InnerText;
foreach (XmlNode xColumn in xml.SelectNodes("/EVENT_INSTANCE/AlterTableActionList/Drop/Columns/Name"))
{
columnName = xColumn.InnerText;
if (t.ColumnList == null || t.ColumnList.Contains(columnName, StringComparer.OrdinalIgnoreCase))
{
sc = new SchemaChange(DdeID, changeType, schemaName, tableName, columnName, null, null);
schemaChanges.Add(sc);
}
}
break;
}
return(schemaChanges);
}
