public override string DropIndex(Index index) {
var sql = new StringBuilder("alter table ");
this.AppendQuotedTableName(sql, index.Map);
sql.Append(" drop index ");
this.AppendQuotedName(sql, index.Name);
return sql.ToString();
}
public override string DropIndex(Index index) {
throw new InvalidOperationException("There is no Ansi-SQL way of dropping an index.");
}
public virtual string CreateIndex(Index index) {
var sql = new StringBuilder(128);
sql.Append("create ");
if (index.IsUnique) {
sql.Append("unique ");
}
sql.Append("index ");
this.AppendQuotedName(sql, index.Name);
sql.Append(" on ");
this.AppendQuotedTableName(sql, index.Map);
sql.Append(" (");
foreach (var column in index.Columns) {
this.AppendQuotedName(sql, column.DbName);
sql.Append(", ");
}
sql.Remove(sql.Length - 2, 2);
sql.Append(")");
return sql.ToString();
}
public abstract string DropIndex(Index index);
public string DropIndex(Index index) {
return this.dialect.DropIndex(index);
}
public override string DropIndex(Index index) {
throw new System.NotImplementedException();
}
public void AddIndex(Index index) {
this.indexes.Add(index);
}
public override string CreateIndex(Index index) {
var statement = base.CreateIndex(index);
if (index.IsUnique && index.Columns.Any(c => c.IsNullable)) {
var whereClause = new StringBuilder();
whereClause.Append(" where ");
bool first = true;
foreach (var column in index.Columns.Where(c => c.IsNullable)) {
if (!first) {
whereClause.Append(" and ");
}
this.AppendQuotedName(whereClause, column.DbName);
whereClause.Append(" is not null");
first = false;
}
statement += whereClause.ToString();
}
return statement;
}